Download Brief History of Internet

Brief History of Internet
Internet, a global network that connects other computer networks, together with software
and protocols for controlling the movement of data. The Internet, often referred to as 'the
Net', stems from a network called ARAPNET (Advanced Research Project Agency
Network), which was initiated in 1969 by a group of universities and private research
groups funded by the US Department of Defense. It now covers almost every country in
the world. Its organization is informal and deliberately nonpolitical--its controllers tend to
concentrate on technical aspects rather than on administrative control.
Brief history web sites
http://www.geocities.com/SiliconValley/2260/links.html
http://www.yahoo.com/Computers_and_Internet/Internet/History/
Introduction to the Internet
The connection of computers can form a network, this connection may be direct (by
direct cabling) or indirect (dial-up). The benefit of connecting computers can exchange
information and share resources such as application software, printers, files, databases or
even other networks
The interconnection of networks among the world forms a dynamic international network
system, which a group of computers, paths or networks may suddenly disappear or appear.
However, different networks may use different transmission methods or protocols, so a
gateway should be needed in order to connect two different networks together.
The Resources in Internet
The Internet offers users a number of basic services including data transfer, electronic
mail, and the ability to access information in remote databases. A notable feature is the
existence of user groups, which allow people to exchange information and debate specific
subjects of interest. In addition, there are a number of high-level services. For example,
MBONE (multicast backbone service) allows the transmission of messages to more than
one destination. It is used in videoconferencing.
The World Wide Web, known as 'the Web', is another high-level Internet service,
developed in the 1990s at CERN in Geneva. It is a service for distributing multimedia
information, including graphics, pictures, sounds, and video as well as text. A feature of
the World Wide Web is that it allows links to other related documents elsewhere on the
Internet. Documents for publication on the Web are presented in a form known as HTML
(hypertext mark-up language). This allows a specification of the page layout and
typography as it will appear on the screen. It also allows the inclusion of active links to
other documents. Generally, these appear on the screen display as highlighted text or as
additional icons. Typically, the user can use a mouse to 'click' on one of these points to
load and view a related document. Many commercial and public organizations now have
their own Web site (specified by an address code) and publish a 'home page', giving
information about the organization.
Up to the mid-1990s, the major users of the Internet were academic and research
organizations. This has begun to change rapidly with individual home users linking in
through commercial access providers and with a growing interest by companies in using
the Internet for publicity, sales, and as a medium for electronic publishing. At the same
time, there are problems with the flow of information across national borders, bringing in
debates about copyright protection, data protection, the publication of pornography, and
ultimately political control and censorship.
Terminology
Internet
It could be said that the internet is the most valuable legacy left over from the Cold War.
It originally came into being as the ARPANet, which was founded by the U.S. Defense
Department‘s Advanced Research Projects Agency (ARPA) to link academic research
centres involved in military research. Nowadays, Internet has grown far beyond its
original conception.
An internet is a network of networks, a kind of meta-network. or a global network that
connects other computer networks, together with software and protocols for controlling
the movement of data. The Internet, often referred to as 'the Net', simply put, the internet
is a set of protocols (rules) for transmitting and exchanging data between networks. In a
broader sense, it is a worldwide and a repository of global information resources.
Transmission Control Protocol/Internet Protocol (TCP/IP)
It is a standard rule set for internet communication. The essence of the internet is not the
wire, but the means for sending and receiving information across the wire. It doesn‘t
matter what type of systems are connected to the internet. The important thing is that they
all use the same protocol, TCP/IP, to communicate with each other.
TCP handles data integrity, and make sure that data gets to the destination without errors,
while IP is the protocol that controls how data moves around on the internet.
Domain Name
Every internet server has a numerical IP (Internet Protocol) address, which usually
consists of four numbers between 0 and 255 separated by periods (something like
185.35.117.0, for instance). Computers prefer numeric addresses of this type because
they are precise. Unfortunately, humans have trouble remembering numbers, and prefer
to use meaningful text addresses, like www.mysite.com. That ‘s what a domain name is: a
text alternative to an IP address. You can use the two interchangeably. If you know the
domain name, you don‘t have to know everything about the IP address.
Most servers have applied for and received a domain name from the Internet Network
Information Centre, which handles domain name registrations. As long as your Web
pages are located on server that has a domain name, you can use that domain name in the
addresses for those Web pages.
Domain Name System
A domain name represents a hierarchy, starting with the most general word on the right
and moving to the most specific on the left. It can include a country code, an organization
code and a site name. For instance, myname.com.hk, reading from right to left, specific
the name of a site in Hong Kong (“hk”) in the commercial (“com”) subcategory, called
“myname”.
There are some country codes listed below
“au” for Australia
“ca” for Canada
“fr” for France
“nz” for New Zealand
“uk” for United States
There are some organisation codes listed below
“edu” for education
“gov” for government
“net” for network
“com” for commercial
“org” for organization
UNIX
It is an operating system which most Web pages reside on Unix servers. Unlike MS-DOS
and Windows systems, Unix systems are case-sensistive file paths and file name.
Therefore, if you see a path and file name, you should type exactly as it appears.
Web Page
A Web page is a hypertext (HTML) document contained in a single file. To have more
than one Web page, you must have more than one file. Remember that a Web page can be
any length, although most Web pages display no more than 2 or 3 screens of data
A Web page is simply a plain text document. All codes are entered into the document as
ordinary text, with none of the binary-level formatting that a word processor would
embed in. When you mark some text as italic, you have to do it by using italic tags in
HTML. This cuts down on the computer overhead, allowing Web pages to remain small
but still pack.
When a browser displays a Web page, the page may appear to contain special graphical
elements like logos or buttons. These graphics don‘t reside in the HTML file, they are
separate files that HTML file reference. For instance <IMG SRC=“mylogo.gif”>.
Web site
The term may have different meanings, some people may regard servers as Web sites,
that is sites on the Web. However, it is more likely to refer to a collection of related and
linked Web pages during a common theme or subject matter as a Web site. The address
that can identify the Web page is the Web site address.
Hypertext
Hypertext is a linking that occurs within and between documents. The basic mechanism
is the capability to embed a hypertext link, a kind of jump point that allows a viewer to
jump from a place in a Web page to any other Web page.
Homepage
When you start your browser, it loads whatever Web page you designate as its homepage.
Most browsers have a command that takes you back to the homepage, usually your ISP‘s
homepage or some common Web browser homepage. Therefore, a homepage may serve
as an entry point to a Web site, and generally keep small, often serving simply as menus
or directories to other Web pages that make up the rest of the Web site. The idea is that a
viewer need only display the homepage and then decide what else to view in the
remainder of the Web site.
Internet Service Provider (ISP)
A company or organization provides you access to the Internet, and the service provider
may also give you space for a personal or non-commercial Web site at little or no cost
Internet Site Addresses
Each page on the Internet has an address that identifies it. This address is used to locate
the page. Internet addresses are called URLs, which stand for Uniform Resource
Locators.
A URL has several parts:
The first part of an Internet address is the protocol type. A protocol is a set of rules used
to exchange information between computers.
For example, the first part of a Web page address is http. It stands for Hypertext Transfer
Protocol, the protocol used on the Web. If the first part of an FTP address is ftp, which
stands for File Transfer Protocol. This type of site store files that users can download.
After the protocol type, the address contains a colon and two forward slashes, such as
http:// or ftp://
Next is the address of the computer (server) on which the site is stored. The computer
identifies the server on the network that contains the site.
For example, www.yahoo.com and www.microsoft.com are all computer addresses.
The domain type is the part of the computer address. This is the three-character extension
at the end of the computer name. The domain type identifies the type of organization of
the host computer.
For example, .com indicates a commercial or business organization, such as
microsoft.com. The .edu extension identifies an educational facility such as umich.edu,
the University of Michigan site.
A URL might also include a page name or address that identifies a specific page within a
site. When you go from the home page of a site to a page within the site, the page address
is added to the URL.
For example, the address of the home page for the Seattle Sidewalk site is
http://seattle.sidewalk.com. If you click a hyperlink from home page to go to the movie
page within the site, the URL for that page is http://seattle.sidewalk.com/movies.
The Web browser displays the address of the current page in the Status bar at the bottom
of the screen and in the Address bar.
Hypertext Markup Language (HTML)
HTML is a computer language, which was developed to mark up, or encode hypertext
document for display on the World Wide Web. An HTML document is a plain ASCII (text)
file with codes (called tags) inserted in the text to define elements in the document.
HTML tags generally have 2 parts, an on-code and an off-code, which contain the text to
be defined. However, a few tags do not require an off-code.
A tag can be represented in the following way, where the ellipsis (...) represents the text
you want to tag:
<Tagname> ... </Tagname>
For example, the following is the tag for a level-one heading in a Web document:
<H1>This is a level-one heading</H1>
HyperText Transfer Protocol (HTTP)
HTTP is a plain text protocol that defines how the Web transports Web pages. Although
an understanding of HTTP is not strictly necessary for the development of CGI
applications, some appreciation of "what's under the hood" will certainly help you to
develop them with more fluency and confidence. As with any field of endeavour, a grasp
of the fundamental underlying principles allows you to visualise the structures and
processes involved in the CGI transactions between clients and servers - giving you a
more comprehensive mental model on which to base your programming.
Underlying the user interface represented by browsers, is the network and the
protocols that travel the wires to the servers or "engines" that process requests, and
return the various media. The protocol of the web is known as HTTP, for Hypertext
Transfer Protocol. HTTP is the underlying mechanism on which CGI operates, and it
directly determines what you can and cannot send or receive via CGI.
Tim Berners-Lee implemented the HTTP protocol in 1990-1 at CERN, the European
Center for High-Energy Physics in Geneva, Switzerland. HTTP stands at the very core of
the World Wide Web. According to the HTTP 1.0specification,
The Hypertext Transfer Protocol (HTTP) is an application-level protocol with the
lightness and speed necessary for distributed, collaborative, hypermedia information
systems. It is a generic, stateless, object-oriented protocol which can be used for many
tasks, such as name servers and distributed object management systems, through
extension of its request methods (commands).