What is the World Wide Web? History Of World Wide Web

World Wide Web? - The Web consists of many millions of internet-connected computers, each with informationon them that their owner has decided to share. These documents can be formed of anythingfrom plain text to multimedia or even 3D objects. These computers, called servers, deliver thisinformation over the Internet to client computers (such as your PC at home) using a protocol

called HTTP (HyperText Transfer Protocol). The HTTP protocol is very simple; essentially it

just provides a mechanism that allows a client to request a document, and a server to send that

document.

• web servers, which store the web pages

• web documents, the pages themselves

• web clients, browsers of many types

World Wide Web As the web has become more and more popular, its capabilities have increased to include such

things as graphics, animations, scripts and even complete computer programs, all embedded into

the pages of the documents. Essentially, the web is the easiest to use of all the internet toolkit

—this is partly why it has become so popular. Various mechanisms allow the viewer to move

around (navigate) the document easily. Clicking on a hyperlink moves you to another part of the

document, or to another document altogether

World Wide Web -The Web's unique features

• universal readership

• hyperlinks/hypertext/hypermedia

• authoring for computers and humans

• availability of information

• felxibility to adapt to new forms of media

The web has become the most predominant of the new digital media, and has provided the

mechanism for many new forms of publishing. There are many reasons why this is so; a few of

them are discussed in the following sections.

• a common format for information (HTML)

• a common access method (HTTP)

• a way to write content...

• ...without having to worry about presentation

As the accessing of information stored on computers has become more widely accepted and used,

the number of methods, and hence the number of computer applications needed, has multiplied.

The web provides a way of integrating these methods and applications, using a common interface

to allow easy access to any information stored on any computer (provided you are authorised

to read it, of course) of World Wide Web

HTML or HyperText Markup Language, the language of the web, was specifically designed to

be easy to learn, and was based around the concept of marking text functionally, to ensure a wide

authorship. Thus, when the author wrote their document, they would be able to concentrate on its

structure, and not worry about its presentation. As it has grown, the web has moved away from

this concept, becoming more complex and more graphical than originally envisioned, which has

led to many presentational features creeping into the HTML standard. Happily though, the core

functions still lie beneath all the complexity, and allow more or less anyone to write their own

web pages quickly and easily, with a minimal set of software tools.

Hypertext and Hypermedia - world Wide Web

• linked documents create a “web of information”

• choice allows reader to choose path through text

• not a new idea - footnotes, bibliographies!

• technology has given links new power

One of the most powerful features of the web is the ability to link documents together using

hyperlinks. On clicking a hyperlink (usually underlined), the browser tries to access the linked document, providing an almost instantaneous cross-referencing system. This creates a non-linear

form of text, known as hypertext. Web pages can also contain multimedia content that can also

be hyperlinked, termed hypermedia. Many theorists believe that hyperlinks change the way we

view and read texts, and certainly the element of choice that hyperlinks give the reader create a

very different reading experience. The idea of hypertext has been around at least as long as books

have contained footnotes or external references/bibliographies, but the computer and the Internet

make following hyperlinks instantaneous (well, almost). See Chapter 4, Writing and Publishing

for more discussion on this topic.

Authoring for computers and humans

• Hypertext Markup Language is designed to be:

• easy for humans to use to present information

• quick to author

• viewable on many computer devices and “platforms”

1. Though it may not seem so when you first see a raw web page, the language it is written in, HTML,

is designed to be easily read by humans, as well as computers. It was developed to make sharinginformation easy, and to make it easy to write documents that would be displayed on many typesof computer. HTML can be interpreted at different levels, even in text-only mode (try turning offthe image-loading in your browser - you'll be surprised at how much faster everything loads, andhow much information is preserved!). Now with devices such as mobile phones having Internetcapabilities, the accessibility of web information is even more important.

Availability of information

• Information available 24/7

• Information often updated in real time

• Access for all on an equal basis

The goal of a web server is to serve information to anyone who requests it; the web pages stored

on the server are made publically available. It's possible to restrict access to certain parts of the

Internet, or to those who have usernames and passwords, but it's not usual - most web sites are

open for all to read their contents. The use of the web as a public space to provoke discussion

or to provide otherwise difficult-to-publish information has been instrumental in its popularity.

Examples of this range from the subversive (terrorists or political groups publishing propaganda)

to the more mundane (businesses publishing time-critical data such as stock information or

market prices).

Surface and deep web

• Only a small part of the web is publicly accessible (the Surface Web)

• Much of the web is hidden inside intranets and commercial sites

• This “Deep Web” is often not searchable

• Deep web is possibly many times the size of surface web

With the rise of commerce on the Web, and the recognition of the market value that certain types

of information can command, parts of the Web have been locked away, hidden behind corporate

intranets and firewalls, passworded sites, and subscription services.

A high proportion of this Deep or Invisible Web is hidden from view, whether from you and I, or

from search engines. Estimates of the size of this deep Web vary, but most agree that it is many

times the size of the Surface Web, i.e. the web that is open and accessible to the public.

Flexibility to adapt to new media

• The HTTP protocol is media neutral

• HTML is text-only; other media items are stored separately

• The HTML language has evolved to embed new media types into web pages

•

The HTTP protocol was specifically designed from the outset to be media neutral, in that

the documents and data it transfers need not be in any particular format. As the document is

transferred, it is accompanied by a header which specifies a MIME type (more about MIME in

the section called “Using Email Attachments”), and this tells the browser viewing the item what

needs to be done to display (or play) the data.

Similarly, the HTML language is designed to use these media items by linking to them from

within a web page. HTML has evolved over the years to allow all kinds of media to be embedded;

from simple static images through video and animations, and even to 3D data.

How does the World Wide Web work? 

• Web servers and web browsers communicate via HTTP

• HTTP ensures that all parts of the web page are delivered

• Web browser decides how these items are displayed

The backbone of the web is the network of webservers across the world. These are really just

computers that have a particular type of software running on them - software that knows how to

speak the HTTP protocol and knows which information stored on the computer should be made

accessible through the web.

It's possible to turn almost any computer into a webserver by downloading and installing server

software (the most popular is Apache, see http://www.apache.org/), though it's not

recommended unless you know what you're doing!

See the Chart of World Wide Web 

see Figure 2.1,

The HyperText Transfer Protocol (HTTP) is actually quite simple. The web browser (or client)

makes a request of a webpage to the server, and the webserver passes the page back to the browser

(see Figure 2.1, “How HTTP works: retrieving a web page”. More cleverly, it also passes back

any images, sounds or other media items back to the browser too.

The web browser is also particularly clever in the way it displays what it retrieves. Web pages

are written in HTML, and the browser knows how to display these correctly, whether you have

a huge flat screen or a tiny screen on a handheld device or phone. The HTML language gives the

browser hints on how to display things, and the browser decides the final layout itself.

I hope You Enjoy The Article of World Wide Web 

POPULAR

• DEEP PACKET INSPECTION
• What is Web
• How work internet
• Who Pay for the internet?
• What is the World Wide Web?
• What is ENCRYPTION