One of the Digital Information Technologies and Architecture
lectures was about Internet and World Wide Web (WWW). Most of the times these
two terms are used interchangeably. However, the definitions are quite
different. www.thesaurus.com suggests
that internet is “a vast computer network linking smaller computer networks
world wide. The Internet includes commercial, educational, governmental, and
other networks, all of which use the same set of communication protocols”; when
WWW is “a system of extensively interlinked hypertext documents: a branch of
internet.”
If we look at the history of internet and www, we see that
internet was proposed by the American military in 1960 with the development of
computers. It does let us to access files, data, etc from central computer and
share resources. Www has been around from 1990 and was created by Tim
Berners-Lee. He “developed the first web browser (…,) including an integrated
editor that could create hypertext documents. He deployed the program to his
and Cailliau’s computers, and they were both communicating with the world’s
first web server (…)” (http://www.livinginternet.com/w/wi_lee.htm
15.10.2011). The World Wide Web allowed view hyperlinked academic documents
remotely and as it proved to be a convenience system in the academic field, www
was introduced to other areas.
The internet and WWW work on the client-server bases.
CLIENT
|
NETWORK
|
SERVER
|
CONNECTION
|
Client sends request to server, server receives request and
responds to it by sending digital message, client receives message, interprets
it and displays as web page.
The example above is one of the simplest ways to represent
information receive process. It’s far more complicated in reality. There are
lots of servers and they hold lots of different information.
Client sends request by using Uniform Resource Locator (URL) which
helps to find right server which contains requested information.
That’s how it looks:
“Conditionsofuse.html” is a file which is placed in folder “conditions”
within “cs” folder. The latter is on the server “www” at “city” university,
which is part of the academic domain “ac” in the United
Kingdom “uk”.
As mentioned earlier “www” indicates World Wide Web and “http” stands for
hypertext transfer protocol, it means that document is a World Wide Web
hypertext document and it’s transferred using hypertext transfer protocol.
Hypertext simply means the text
which contains links to other texts and is used in World Wide Web. Furthermore,
it means that documents can be linked between each other even if they are
stored on different servers. Mark-up elements are used to achieve it and the
best example is HTML (Hypertext Mark-up Language).
So, it was all theoretical part of
the Internet and World Wide Web. The next thing is the practical exercises: Learning to use and publish HTML.
Before I started creating my HTML
I looked at some elements as paragraph, line brake and horizontal rules in www.w3schools.com (15.10.2011).
<p> defines paragraph in
HTML document. Like most of the elements it has start tag <p> and end tag
<p/>. Between these two tags is element content; the text which you would
like to appear in that paragraph.
Line brake <br> is an empty
element and it doesn’t require end tag. You insert it before the text which you
would like to appear in a new line without starting a new paragraph.
Horizontal rules <hr> is
another empty element. It is used to separate text.
All three elements have
attributes. <p> supports a few standard attributes such as class, style,
title, id and others. The listed attributes are supported by <br> element
as well as <hr>.
After familiarising myself with
another few essential elements like <html>, <head> and <body>
I started creating HTML document in an html editor.
My first.html includes two links
to documents on different servers and two links to html pages created by me and
saved on City server. The most fascinating part of creating HTML document to me
personally was linking and inserting pictures. The rest was quite straight
forward. As we used html editor all we had to do was to fill in a template.
Therefore I will explain documents linking and inserting picture.
Links in html are specified by
<a> and it’s attribute href which specifies the destination. Attribute,
URL and link text in this particular order has to be between anchor tags
<a> and </a>. The anchor tag itself can be inserted anywhere in
text.
Something like this:
Little bits and pieces
<a href=”www.student.city.ac.uk/~abkc925/index.html”>
about me </a>.
The link in the text will be
displayed like this: about me.
Tag for images is <img> and
it doesn’t have closing tag. Attribute to display picture is src. Width and height specifies size of the
picture.
<img src=”lithuanian big.jpg”
width=”444” height=”251”>
For the picture to be displayed in
an html document it has to be in the same folder as html document. If it
happens that picture can not be displayed there is an alt attribute which
specifies an alternate text for the image. It would be placed at the end of the
element content.
<img src=”lithuanian big.jpg”
width=”444” hight=”251” alt=”Local Image: Trakai”>
If picture is not in a local file
but on the World Wide Web URL has to be used to display it.
Overall, I learned differences
between the Internet and The World Wide Web. Furthermore, I created and
published my HTML document linked with another two HTML documents as well as
links to documents on different servers.
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