Internet technology
Content
Internet technology
Internet is the world wide publically accessible network of inter connected computer
network that transmit a data by packet switcing using the standard internet protocol. The roots of the
internet lie in a project called ARPANET which was sponsored by the United states department of
defence researches projects agency. The Internet is a worldwide, publicly accessible series of
interconnected computer networks that transmit data by packet switching using the standard Internet
Protocol (IP). It is a "network of networks" that consists of millions of smaller domestic, academic,
business, and government networks, which together carry various information and services, such as
electronic mail, online chat, file transfer, and the interlinked web pages and other resources of the
World Wide Web (WWW).
History of internet
In the 1950s and early 1960s, prior to the widespread inter-networking that led to the Internet,
most communication networks were limited by their nature to only allow communications between
the stations on the network. Some networks had gateways or bridges between them, but these
bridges were often limited or built specifically for a single use. One prevalent computer networking
method was based on the central mainframe method, simply allowing its terminals to be connected
via long leased lines.
Packet Switching
At the tip of the inter-networking problem lay the issue of connecting separate physical
networks to form one logical network, with much wasted capacity inside the assorted separate
network. During the 1960s, Donald Davies (NPL), Paul Baran (RAND Corporation), and Leonard
Kleinrock (MIT) developed and implemented packet switching. The notion that the Internet was
developed to survive a nuclear attack has its roots in the early theories developed by RAND, but is
an urban legend, not supported by any Internet Engineering Task Force or other document. Early
networks used for the command and control of nuclear forces were message switched, not packetswitched, although current strategic military networks are, indeed, packet-switching and
connectionless. Baran's research had approached packet switching from studies of decentralisation to
avoid combat damage compromising the entire network
Accessing the internet via telephone system
To access the internet over a phone line, the following are needed
A computer
A modem
An available telephone line
The appropriate software, including a communication programme.
Modem
Data inside the computer is stored in a form that is different from the data transmitted over a
phone line. Computer data is stored in a digital format, while phone line transmit data in analog
format. The proscess of converting analog format to digital format is called modulation. And the
process of converting analog data back to digital format is known as demodulation. Thus, the device
use to act as an interface between our computer and the phone system is caled a
modulator/demodulator or a Modem
Router
Router is a piece of hardware or software that connect two or more networks. A router
function as a sorter as it looks at address and passes bits of information to their proper destination.
Software routers are sometimes refered as gateways.
Internet access
Common methods of home access include dial-up, landline broadband (over coaxial cable,
fiber optic or copper wires), Wi-Fi, satellite and 3G technology cell phones.Public places to use the
Internet include libraries and Internet cafes, where computers with Internet connections are
available. There are also Internet access points in many public places such as airport halls and coffee
shops, in some cases just for brief use while standing. Various terms are used, such as "public
Internet kiosk", "public access terminal", and "Web payphone". Many hotels now also have public
terminals, though these are usually fee-based. It is widely accessed for various usage like ticket
booking, bank deposit, online payment etc.e.g. 68% people have access to internet who are frequent
fliers in India.now it is accessed through wireless. Wi-Fi provides wireless access to computer
networks, and therefore can do so to the Internet itself. Hotspots providing such access include WiFi-cafes, where a would-be user needs to bring their own wireless-enabled devices such as a laptop
or PDA. These services may be free to all, free to customers only, or fee-based. A hotspot need not
be limited to a confined location. The whole campus or park, or even the entire city can be enabled.
Grassroots efforts have led to wireless community networks. Commercial WiFi services covering
large city areas are in place in London, Vienna, Toronto, San Francisco, Philadelphia, Chicago and
Pittsburgh. The Internet can then be accessed from such places as a park bench.Apart from Wi-Fi,
there have been experiments with proprietary mobile wireless networks like Ricochet, various highspeed data services over cellular phone networks, and fixed wireless services.High-end mobile
phones such as smartphones generally come with Internet access through the phone network. Web
browsers such as Opera are available on these advanced handsets, which can also run a wide variety
of other Internet software. More mobile phones have Internet access than PCs, though this is not as
widely used. An Internet access provider and protocol matrix differentiates the methods used to get
online
TCP/IP
It stands for transmission control protocol or internet protocol, the protocol governing
communication between all computers network. TCP/IP is a set of insruction that detates how
packets of information are sent acros multiple network and control data procesing transmission.
Internet protocol suite.
The Internet protocol suite is the set of communications protocols that implement the
protocol stack on which the Internet and most commercial networks run. It has also been referred to
as the TCP/IP protocol suite, which is named after two of the most important protocols in it: the
Transmission Control Protocol (TCP) and the Internet Protocol (IP), which were also the first two
networking protocols defined. Today's IP networking represents a synthesis of two developments
that began in the 1970s, namely LANs (Local Area Networks) and the Internet, both of which have
revolutionized computing.The Internet Protocol suite—like many protocol suites—can be viewed as
a set of layers. Each layer solves a set of problems involving the transmission of data, and provides a
well-defined service to the upper layer protocols based on using services from some lower layers.
Upper layers are logically closer to the user and deal with more abstract data, relying on lower layer
protocols to translate data into forms that can eventually be physically transmitted. The TCP/IP
reference model consists of four layers The Internet protocol suite came from work done by DARPA
in the early 1970s. After building the pioneering ARPANET, DARPA started work on a number of
other data transmission technologies. In 1972, Robert E. Kahn was hired at the DARPA Information
Processing Technology Office, where he worked on both satellite packet networks and ground-based
radio packet networks, and recognized the value of being able to communicate across them. In the
spring of 1973, Vinton Cerf, the developer of the existing ARPANET Network Control Program
(NCP) protocol, joined Kahn to work on open-architecture interconnection models with the goal of
designing the next protocol for the ARPANET.DARPA then contracted with BBN Technologies,
Stanford University, and the University College London to develop operational versions of the
protocol on different hardware platforms. Four versions were developed: TCP v1, TCP v2, a split
into TCP v3 and IP v3 in the spring of 1978, and then stability with TCP/IP v4 — the standard
protocol still in use on the Internet today.
Implementations
Today, most commercial operating systems include and install the TCP/IP stack by default.
For most users, there is no need to look for implementations. TCP/IP is included in all commercial
Unix systems, Mac OS X, and all free-software Unix-like systems such as Linux distributions and
BSD systems, as well as Microsoft Windows.Unique implementations include Lightweight TCP/IP,
an open source stack designed for embedded systems and KA9Q NOS, a stack and associated
protocols for amateur packet radio systems and personal computers connected via serial lines.
IP address
Evry single machine connect to network consist of four part no. called IP address.
Eg: 202-52-141-21
Internet addressing
Standard internet addressing
On the internet, the word address always refers to an electronic address. All the internet
address follow the same form: the persons user name, followed by an @ character ( the ‘at’ sign)
followed by the name of computer .
Eg: [email protected] In this case, the user name is info and the name of computer is rit.ac.in
Each person has an user name called user id. It is the user id that we use as the first part of
someones address the part of the address after rhe @ character is called domain. Thus the standard
form of all internet address is : userid@domain
Domain name system( DNS)
Part of the internet that keeps the track of address of computers for matching between
numeric version address and character version address is called domain name system. DNS is a
TCP/IP srvice for translation of domain name to and from ip address.
Domain
Meaning
com
commercial organization
edu
educational institution
gov
government
int
international organization
mil
military organization
in
india
au
australia
us
united states
UUCP
UUCP is a Unix vased networking facility consisting of a family of programs. Witihin the
UUCP family, there are a no.of separate programs, each of which performs a different function. All
unix systems come with a built in network system called UUCP.although the job of UUCP is to
connect unix computers, it is not powerful as TCP/IP.UUCP doesnot provides a remote login facility.
Language
The prevalent language for communication on the Internet is English. This may be a result of
the Internet's origins, as well as English's role as the lingua franca. It may also be related to the poor
capability of early computers, largely originating in the United States, to handle characters other than
those in the English variant of the Latin alphabet.After English (30% of Web visitors) the mostrequested languages on the World Wide Web are Chinese 14%, Spanish 8%, Japanese 8%, German
5%, French 5%, Portuguese 3.5%, Korean 3%, Italian 3% and Arabic 2.5% (from Internet World
Stats, updated January 11, 2007).By continent, 36% of the world's Internet users are based in Asia,
29% in Europe, and 21% in North America ( updated January 11, 2007).The Internet's technologies
have developed enough in recent years, especially in the use of Unicode, that good facilities are
available for development and communication in most widely used languages
The World Wide Web
The World Wide Web (commonly shortened to the Web) is a system of interlinked,
hypertext documents accessed via the Internet. With a web browser, a user views web pages that
may contain text, images, videos, and other multimedia and navigates between them using
hyperlinks. The World Wide Web was created in 1989 by Sir Tim Berners-Lee, working at CERN in
Geneva, Switzerland. Since then, Berners-Lee has played an active role in guiding the development
of web standards (such as the markup languages in which web pages are composed), and in recent
years has advocated his vision of a Semantic Web. Robert Cailliau, also at CERN, was an early
evangelist for the project.
How the Web works
Viewing a web page on the World Wide Web normally begins either by typing the URL of
the page into a web browser, or by following a hyperlink to that page or resource. The web browser
then initiates a series of communication messages, behind the scenes, in order to fetch and display
it.First, the server-name portion of the URL is resolved into an IP address using the global,
distributed Internet database known as the domain name system, or DNS. This IP address is
necessary to contact and send data packets to the web server.The browser then requests the resource
by sending an HTTP request to the web server at that particular address. In the case of a typical web
page, the HTML text of the page is requested first and parsed immediately by the web browser,
which will then make additional requests for images and any other files that form a part of the page.
Statistics measuring a website's popularity are usually based on the number of 'page views' or
associated server 'hits', or file requests, which take place.Having received the required files from the
web server, the browser then renders the page onto the screen as specified by its HTML, CSS, and
other web languages. Any images and other resources are incorporated to produce the on-screen web
page that the user sees.
Publishing web pages
Web page production is available to individuals outside the mass media. In order to publish a
web page, one does not have to go through a publisher or other media institution, and potential
readers could be found in all corners of the globe.Many different kinds of information are available
on the Web, and for those who wish to know other societies, cultures, and peoples, it has become
easier.The increased opportunity to publish materials is observable in the countless personal and
social networking pages, as well as sites by families, small shops, etc., facilitated by the emergence
of free web hosting services.
HTTP
Hypertext Transfer Protocol (HTTP) is a communications protocol used to transfer or
convey information on intranets and the World Wide Web. Its original purpose was to provide a way
to publish and retrieve hypertext pages. Development of HTTP was coordinated by the W3C (World
Wide Web Consortium) and the IETF (Internet Engineering Task Force), culminating in the
publication of a series of RFCs, most notably RFC 2616 (June 1999), which defines HTTP/1.1, the
version of HTTP in common use.HTTP is a request/response protocol between a client and a server.
The client making an HTTP request - such as a web browser, spider, or other end-user tool - is
referred to as the user agent. The responding server - which stores or creates resources such as
HTML files and images - is called the origin server. In between the user agent and origin server may
be several intermediaries, such as proxies, gateways, and tunnels. HTTP is not constrained to using
TCP/IP and its supporting layers, although this is its most popular application on the Internet. Indeed
HTTP can be "implemented on top of any other protocol on the Internet, or on other networks. HTTP
only presumes a reliable transport; any protocol that provides such guarantees can be
used."Typically, an HTTP client initiates a request by establishing a Transmission Control Protocol
(TCP) connection to a particular port on a host (port 80 by default; see List of TCP and UDP port
numbers). An HTTP server listening on that port waits for the client to send a request message.Upon
receiving the request, the server sends back a status line, such as "HTTP/1.1 200 OK", and a
message of its own, the body of which is perhaps the requested file, an error message, or some other
information.
URLs
URL stands for Uniform Resource Locator.Each URL refers to one specific internet resource.
Within this system, there is a unique URL for any hypertext item on the net. Moreover, there are also
unique URLs for non-hypertext item from other services,such as gophers, anonimous ftp sites
etc.For example. An URL that starts with ‘http’ stands for hypertext transfer protocol as described
above,URL starts with ‘gopher’ refers to gopher items. An URL start with ftp; refers to an ftp
resource.
What is the gopher?
The gpoher system is a pwerful that allows to access many of the resources of the internet in
a simple, consistant manner. To access the system, run a programme called gopherclient.
What is Ftp?
Ftp stands for File Transfer Protocol. It is the internet service thatr allows to transfer files
from one computer to another. Like all computer system, ftp has a server client sstem. In ftp
technology one computer is called the Local Host and the other is called the Remote Host.
Anonymous Ftp
It is a facility that lets you connect certain remote hosts and download files without having to
be registered as a user. To do so login using a special user name: anonymous.
ICANN
The Internet Corporation for Assigned Names and Numbers (ICANN) is the authority that
coordinates the assignment of unique identifiers on the Internet, including domain names, Internet
Protocol (IP) addresses, and protocol port and parameter numbers. A globally unified namespace
(i.e., a system of names in which there is one and only one holder of each name) is essential for the
Internet to function. ICANN is headquartered in Marina del Rey, California, but is overseen by an
international board of directors drawn from across the Internet technical, business, academic, and
non-commercial communities. The US government continues to have the primary role in approving
changes to the root zone file that lies at the heart of the domain name system. Because the Internet is
a distributed network comprising many voluntarily interconnected networks, the Internet, as such,
has no governing body. ICANN's role in coordinating the assignment of unique identifiers
distinguishes it as perhaps the only central coordinating body on the global Internet, but the scope of
its authority extends only to the Internet's systems of domain names, IP addresses, and protocol port
and parameter numbers.
Common Application of internet
1. E-mail
2. The World Wide Web
3. Remote access
4. Collaboration
5. File sharing
6. Streaming media
7. Voice telephony (VoIP)
8. Censorship
9. Marketing
Internet is the world wide publically accessible network of inter connected computer
network that transmit a data by packet switcing using the standard internet protocol. The roots of the
internet lie in a project called ARPANET which was sponsored by the United states department of
defence researches projects agency. The Internet is a worldwide, publicly accessible series of
interconnected computer networks that transmit data by packet switching using the standard Internet
Protocol (IP). It is a "network of networks" that consists of millions of smaller domestic, academic,
business, and government networks, which together carry various information and services, such as
electronic mail, online chat, file transfer, and the interlinked web pages and other resources of the
World Wide Web (WWW).
History of internet
In the 1950s and early 1960s, prior to the widespread inter-networking that led to the Internet,
most communication networks were limited by their nature to only allow communications between
the stations on the network. Some networks had gateways or bridges between them, but these
bridges were often limited or built specifically for a single use. One prevalent computer networking
method was based on the central mainframe method, simply allowing its terminals to be connected
via long leased lines.
Packet Switching
At the tip of the inter-networking problem lay the issue of connecting separate physical
networks to form one logical network, with much wasted capacity inside the assorted separate
network. During the 1960s, Donald Davies (NPL), Paul Baran (RAND Corporation), and Leonard
Kleinrock (MIT) developed and implemented packet switching. The notion that the Internet was
developed to survive a nuclear attack has its roots in the early theories developed by RAND, but is
an urban legend, not supported by any Internet Engineering Task Force or other document. Early
networks used for the command and control of nuclear forces were message switched, not packetswitched, although current strategic military networks are, indeed, packet-switching and
connectionless. Baran's research had approached packet switching from studies of decentralisation to
avoid combat damage compromising the entire network
Accessing the internet via telephone system
To access the internet over a phone line, the following are needed
A computer
A modem
An available telephone line
The appropriate software, including a communication programme.
Modem
Data inside the computer is stored in a form that is different from the data transmitted over a
phone line. Computer data is stored in a digital format, while phone line transmit data in analog
format. The proscess of converting analog format to digital format is called modulation. And the
process of converting analog data back to digital format is known as demodulation. Thus, the device
use to act as an interface between our computer and the phone system is caled a
modulator/demodulator or a Modem
Router
Router is a piece of hardware or software that connect two or more networks. A router
function as a sorter as it looks at address and passes bits of information to their proper destination.
Software routers are sometimes refered as gateways.
Internet access
Common methods of home access include dial-up, landline broadband (over coaxial cable,
fiber optic or copper wires), Wi-Fi, satellite and 3G technology cell phones.Public places to use the
Internet include libraries and Internet cafes, where computers with Internet connections are
available. There are also Internet access points in many public places such as airport halls and coffee
shops, in some cases just for brief use while standing. Various terms are used, such as "public
Internet kiosk", "public access terminal", and "Web payphone". Many hotels now also have public
terminals, though these are usually fee-based. It is widely accessed for various usage like ticket
booking, bank deposit, online payment etc.e.g. 68% people have access to internet who are frequent
fliers in India.now it is accessed through wireless. Wi-Fi provides wireless access to computer
networks, and therefore can do so to the Internet itself. Hotspots providing such access include WiFi-cafes, where a would-be user needs to bring their own wireless-enabled devices such as a laptop
or PDA. These services may be free to all, free to customers only, or fee-based. A hotspot need not
be limited to a confined location. The whole campus or park, or even the entire city can be enabled.
Grassroots efforts have led to wireless community networks. Commercial WiFi services covering
large city areas are in place in London, Vienna, Toronto, San Francisco, Philadelphia, Chicago and
Pittsburgh. The Internet can then be accessed from such places as a park bench.Apart from Wi-Fi,
there have been experiments with proprietary mobile wireless networks like Ricochet, various highspeed data services over cellular phone networks, and fixed wireless services.High-end mobile
phones such as smartphones generally come with Internet access through the phone network. Web
browsers such as Opera are available on these advanced handsets, which can also run a wide variety
of other Internet software. More mobile phones have Internet access than PCs, though this is not as
widely used. An Internet access provider and protocol matrix differentiates the methods used to get
online
TCP/IP
It stands for transmission control protocol or internet protocol, the protocol governing
communication between all computers network. TCP/IP is a set of insruction that detates how
packets of information are sent acros multiple network and control data procesing transmission.
Internet protocol suite.
The Internet protocol suite is the set of communications protocols that implement the
protocol stack on which the Internet and most commercial networks run. It has also been referred to
as the TCP/IP protocol suite, which is named after two of the most important protocols in it: the
Transmission Control Protocol (TCP) and the Internet Protocol (IP), which were also the first two
networking protocols defined. Today's IP networking represents a synthesis of two developments
that began in the 1970s, namely LANs (Local Area Networks) and the Internet, both of which have
revolutionized computing.The Internet Protocol suite—like many protocol suites—can be viewed as
a set of layers. Each layer solves a set of problems involving the transmission of data, and provides a
well-defined service to the upper layer protocols based on using services from some lower layers.
Upper layers are logically closer to the user and deal with more abstract data, relying on lower layer
protocols to translate data into forms that can eventually be physically transmitted. The TCP/IP
reference model consists of four layers The Internet protocol suite came from work done by DARPA
in the early 1970s. After building the pioneering ARPANET, DARPA started work on a number of
other data transmission technologies. In 1972, Robert E. Kahn was hired at the DARPA Information
Processing Technology Office, where he worked on both satellite packet networks and ground-based
radio packet networks, and recognized the value of being able to communicate across them. In the
spring of 1973, Vinton Cerf, the developer of the existing ARPANET Network Control Program
(NCP) protocol, joined Kahn to work on open-architecture interconnection models with the goal of
designing the next protocol for the ARPANET.DARPA then contracted with BBN Technologies,
Stanford University, and the University College London to develop operational versions of the
protocol on different hardware platforms. Four versions were developed: TCP v1, TCP v2, a split
into TCP v3 and IP v3 in the spring of 1978, and then stability with TCP/IP v4 — the standard
protocol still in use on the Internet today.
Implementations
Today, most commercial operating systems include and install the TCP/IP stack by default.
For most users, there is no need to look for implementations. TCP/IP is included in all commercial
Unix systems, Mac OS X, and all free-software Unix-like systems such as Linux distributions and
BSD systems, as well as Microsoft Windows.Unique implementations include Lightweight TCP/IP,
an open source stack designed for embedded systems and KA9Q NOS, a stack and associated
protocols for amateur packet radio systems and personal computers connected via serial lines.
IP address
Evry single machine connect to network consist of four part no. called IP address.
Eg: 202-52-141-21
Internet addressing
Standard internet addressing
On the internet, the word address always refers to an electronic address. All the internet
address follow the same form: the persons user name, followed by an @ character ( the ‘at’ sign)
followed by the name of computer .
Eg: [email protected] In this case, the user name is info and the name of computer is rit.ac.in
Each person has an user name called user id. It is the user id that we use as the first part of
someones address the part of the address after rhe @ character is called domain. Thus the standard
form of all internet address is : userid@domain
Domain name system( DNS)
Part of the internet that keeps the track of address of computers for matching between
numeric version address and character version address is called domain name system. DNS is a
TCP/IP srvice for translation of domain name to and from ip address.
Domain
Meaning
com
commercial organization
edu
educational institution
gov
government
int
international organization
mil
military organization
in
india
au
australia
us
united states
UUCP
UUCP is a Unix vased networking facility consisting of a family of programs. Witihin the
UUCP family, there are a no.of separate programs, each of which performs a different function. All
unix systems come with a built in network system called UUCP.although the job of UUCP is to
connect unix computers, it is not powerful as TCP/IP.UUCP doesnot provides a remote login facility.
Language
The prevalent language for communication on the Internet is English. This may be a result of
the Internet's origins, as well as English's role as the lingua franca. It may also be related to the poor
capability of early computers, largely originating in the United States, to handle characters other than
those in the English variant of the Latin alphabet.After English (30% of Web visitors) the mostrequested languages on the World Wide Web are Chinese 14%, Spanish 8%, Japanese 8%, German
5%, French 5%, Portuguese 3.5%, Korean 3%, Italian 3% and Arabic 2.5% (from Internet World
Stats, updated January 11, 2007).By continent, 36% of the world's Internet users are based in Asia,
29% in Europe, and 21% in North America ( updated January 11, 2007).The Internet's technologies
have developed enough in recent years, especially in the use of Unicode, that good facilities are
available for development and communication in most widely used languages
The World Wide Web
The World Wide Web (commonly shortened to the Web) is a system of interlinked,
hypertext documents accessed via the Internet. With a web browser, a user views web pages that
may contain text, images, videos, and other multimedia and navigates between them using
hyperlinks. The World Wide Web was created in 1989 by Sir Tim Berners-Lee, working at CERN in
Geneva, Switzerland. Since then, Berners-Lee has played an active role in guiding the development
of web standards (such as the markup languages in which web pages are composed), and in recent
years has advocated his vision of a Semantic Web. Robert Cailliau, also at CERN, was an early
evangelist for the project.
How the Web works
Viewing a web page on the World Wide Web normally begins either by typing the URL of
the page into a web browser, or by following a hyperlink to that page or resource. The web browser
then initiates a series of communication messages, behind the scenes, in order to fetch and display
it.First, the server-name portion of the URL is resolved into an IP address using the global,
distributed Internet database known as the domain name system, or DNS. This IP address is
necessary to contact and send data packets to the web server.The browser then requests the resource
by sending an HTTP request to the web server at that particular address. In the case of a typical web
page, the HTML text of the page is requested first and parsed immediately by the web browser,
which will then make additional requests for images and any other files that form a part of the page.
Statistics measuring a website's popularity are usually based on the number of 'page views' or
associated server 'hits', or file requests, which take place.Having received the required files from the
web server, the browser then renders the page onto the screen as specified by its HTML, CSS, and
other web languages. Any images and other resources are incorporated to produce the on-screen web
page that the user sees.
Publishing web pages
Web page production is available to individuals outside the mass media. In order to publish a
web page, one does not have to go through a publisher or other media institution, and potential
readers could be found in all corners of the globe.Many different kinds of information are available
on the Web, and for those who wish to know other societies, cultures, and peoples, it has become
easier.The increased opportunity to publish materials is observable in the countless personal and
social networking pages, as well as sites by families, small shops, etc., facilitated by the emergence
of free web hosting services.
HTTP
Hypertext Transfer Protocol (HTTP) is a communications protocol used to transfer or
convey information on intranets and the World Wide Web. Its original purpose was to provide a way
to publish and retrieve hypertext pages. Development of HTTP was coordinated by the W3C (World
Wide Web Consortium) and the IETF (Internet Engineering Task Force), culminating in the
publication of a series of RFCs, most notably RFC 2616 (June 1999), which defines HTTP/1.1, the
version of HTTP in common use.HTTP is a request/response protocol between a client and a server.
The client making an HTTP request - such as a web browser, spider, or other end-user tool - is
referred to as the user agent. The responding server - which stores or creates resources such as
HTML files and images - is called the origin server. In between the user agent and origin server may
be several intermediaries, such as proxies, gateways, and tunnels. HTTP is not constrained to using
TCP/IP and its supporting layers, although this is its most popular application on the Internet. Indeed
HTTP can be "implemented on top of any other protocol on the Internet, or on other networks. HTTP
only presumes a reliable transport; any protocol that provides such guarantees can be
used."Typically, an HTTP client initiates a request by establishing a Transmission Control Protocol
(TCP) connection to a particular port on a host (port 80 by default; see List of TCP and UDP port
numbers). An HTTP server listening on that port waits for the client to send a request message.Upon
receiving the request, the server sends back a status line, such as "HTTP/1.1 200 OK", and a
message of its own, the body of which is perhaps the requested file, an error message, or some other
information.
URLs
URL stands for Uniform Resource Locator.Each URL refers to one specific internet resource.
Within this system, there is a unique URL for any hypertext item on the net. Moreover, there are also
unique URLs for non-hypertext item from other services,such as gophers, anonimous ftp sites
etc.For example. An URL that starts with ‘http’ stands for hypertext transfer protocol as described
above,URL starts with ‘gopher’ refers to gopher items. An URL start with ftp; refers to an ftp
resource.
What is the gopher?
The gpoher system is a pwerful that allows to access many of the resources of the internet in
a simple, consistant manner. To access the system, run a programme called gopherclient.
What is Ftp?
Ftp stands for File Transfer Protocol. It is the internet service thatr allows to transfer files
from one computer to another. Like all computer system, ftp has a server client sstem. In ftp
technology one computer is called the Local Host and the other is called the Remote Host.
Anonymous Ftp
It is a facility that lets you connect certain remote hosts and download files without having to
be registered as a user. To do so login using a special user name: anonymous.
ICANN
The Internet Corporation for Assigned Names and Numbers (ICANN) is the authority that
coordinates the assignment of unique identifiers on the Internet, including domain names, Internet
Protocol (IP) addresses, and protocol port and parameter numbers. A globally unified namespace
(i.e., a system of names in which there is one and only one holder of each name) is essential for the
Internet to function. ICANN is headquartered in Marina del Rey, California, but is overseen by an
international board of directors drawn from across the Internet technical, business, academic, and
non-commercial communities. The US government continues to have the primary role in approving
changes to the root zone file that lies at the heart of the domain name system. Because the Internet is
a distributed network comprising many voluntarily interconnected networks, the Internet, as such,
has no governing body. ICANN's role in coordinating the assignment of unique identifiers
distinguishes it as perhaps the only central coordinating body on the global Internet, but the scope of
its authority extends only to the Internet's systems of domain names, IP addresses, and protocol port
and parameter numbers.
Common Application of internet
1. E-mail
2. The World Wide Web
3. Remote access
4. Collaboration
5. File sharing
6. Streaming media
7. Voice telephony (VoIP)
8. Censorship
9. Marketing
