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How the Web Works
by Anthony Stai
Many people think the Internet and the web are the same thing. In fact,
the Internet is simply a global network of computers – the web
runs on top of the Internet, and makes it useful for us. So how does
the web work?
The Invention of the Web.
The web was invented by a man named Tim Berners-Lee in 1989 –
that's 20 years after the start of the Internet. People had been trying
to work out effective ways of sending information around on the
Internet for a while at that point (email was invented in 1971, for
example), but there hadn't been any systems that had really harnessed
the net's potential.
The web changed everything. Berners-Lee's big idea was to apply the
idea of links to the Internet: the web would be a mass of pages that
you could move between by clicking on links. He came up with a format
for these pages (HTML), and wrote the first web browser to view them
with, as well as the first web server for sending them to other
people's web browsers.
Links might not seem like much now, but at the time they were
revolutionary. Imagine what the web would be like if you had to keep
typing long addresses every time you wanted to move from one page to
the next, or using long numbered menu systems that work differently
from one site to the next. Without the web, having Internet access
would be pretty useless.
Servers and Browsers.
Any time you use a web browser (like Internet Explorer or Mozilla Firefox), you're using the web. How? Well, it works like this:
1. You open your web browser, and it goes to your home page. From
there, you can click links to other websites, or to other parts of the
same website. If your home page is a search engine, then you can type
in a search and click links in the search results. If you know the
address of a site you want to go to, you can type it in, and then click
more links from there to keep going.
2. Each time you click a link, your browser looks at two things about
it: the name of the web server it links to, and the name of the page it
links to on that server. For example, the address
'http://www.example.com/mypage.html' tells the web browser to get the
page called mypage.html from the server at www.example.com, using HTTP
(Hypertext Transfer Protocol). This server is a real computer,
connected to the Internet, that has the page you want to read stored on
its hard disk.
3. To find out where this server is, your web browser looks it up using
DNS (Domain Name System), which turns the text address into a number.
This IP (Internet Protocol) address consists of four numbers between 0
and 255 – it looks like a phone number. The Internet is set up to
make it easy to find a server anywhere in the world once you know its
IP address, and it can easily find the quickest route from your ISP
(Internet Service Provider) to the server, and establish communication.
This whole process, from DNS lookup to connection, will often take much
less than a second.
4. Your web browser then sends an HTTP request to that web server, and
the web server responds by sending back the HTML (Hypertext Markup
Language) code for that page. Your web browser turns this code into a
page that you can view. From there, you can click more links to start
the process over again.
Of course, all this is quite simplified: modern browsers and servers
send around much more than HTML code. You can use the web to download
anything now, from pictures to programs, but it all works in basically
the same way.
If something goes wrong somewhere in this process, then you'll get an
error: 'the page cannot be displayed', for example, usually means that
the server's name was wrong, or that it doesn't have the page you
wanted. You might also see errors saying that the server is currently
too busy with other people's requests to respond, or that the page you
wanted has moved. In each case, the best thing to do is to follow the
instructions on the error page, which usually means checking the
address and trying again.
About
The Author:
Anthony Stai invites you to
take your
website to the next level. Get one of the best Search Engine
Optimization (SEO) books on the market for Free! Learn the techniques
that differentiate the amateurs from the pros. Get your book at http://www.makemoneyonline4you.com/seo.html
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