Internet Tech
Home
Curriculum Vitae
Interests
Javascript
|
|
Internet Technology
"The internet mixes computing and communications tecnology, making information
instantly and conveniently accessible worldwide."
History of the Internet
In the late 1960s, ARPA (Advanced Research Projects Agency) of the Department
of Defense developed a means of networking the main computer systems of approximately 12
ARPA funded universities and research institutions. They were to be connected with
communication lines operating at 56kb per second. They called it the ARPAnet...
Rather than sharing each others computers, as previously intended, the key benefit of this
network was that it allowed researchers to communicate easily and quickly amongst themselves via
electronic mail (e-mail). The primary goal of the ARPAnet was to
allow multiple users to send and receive information at the same time over the same
communications paths (telephone lines). The protocols for communicating over the ARPAnet
became known as TCP (Transmission Control Protocol) and this ensured
that messages were properly distributed from sender to receiver and that those messages arrived
intact.
At this time, organisations worldwide were implementing networks of their own - for communicating
within the organisation and between other organisations and the challenge arose to get these
specific networks to intercommunicate...accomplished with the introduction of the
Internetworking Protocol.....TCP/IP
Initially use of internet limited to universities, research institutions and military before the
government decided to allow access to the Internet for commercial purposes. Businesses began to
realise the superb opportunities provided by the Internet leading to massive investment in its
development.
History of the World Wide Web
The WWW allows computer users to locate and view multimedia based documents
on any subject. Although the concept of the internet was conceived in the 1960s, the
World Wide Web was developed in 1990 by Tim Berners-Lee of CERN (European
Laboratory for Particle Physics). The WWW is distributed over a network
of 10 million computers, each of which acts as a web server.
The World Wide Web obeys communications protocol called HTTP (HyperText Transfer Protocol).
Each webpage has a unique HTTP address allowing browsers to retrieve that page
from the Internet.
A URL (Uniform Resource Locator) is another name for HTTP
address i.e. web address. Every website has one and they are split into 3 parts web server name,
directory path, filename.
A typical URL would be as follows: http://www.ucc.ie/registration/index.html
Protocol:
|
|
http://
|
Domain:
|
|
|
www.ucc.ie |
Folder: |
|
|
|
/registration |
File: |
|
|
|
|
/index.html |
The domain name helps identify and locate computers on the internet. It acts as an alias
to a series of numbers called an IP address.
Although many URLs begin with "www", this is not a necessity as the
characters before the first period in the domain name are not part of the registered domain.
Steps in accessing website
- Browser sends a request to DNS
- DNS(Domain Name Server) translates the web servers name into a numeric
Internet Protocol(IP) address.Every computer with internet access has a unique
IP address and all internet communications rely on this address.
- Request sent from the web browser to the IP address tells the web server at
the specified IP address which the web pages is being requested by supplying a
directory path and filename
- Browser sends a return IP address so that web server will know where to
send the web page
A web server is a computer running specialsed software which is always connected to
the Internet. When you enter a URL you are sending a request to the server that
stores all the requested information to display it the way you want to view it. This computer
then "serves" and displays the information via your web browser on your "client" PC.
A website is a directory/folder that is located on the server. Within the site, there
may be several folders which contain various sections of the website. It is a collection of
webpages.
A web browser is software that runs on the client PC enabling you to view web pages. They
retrieve documents from web servers and display them on a computer monitor. Examples include:
Netscape Navigator and MS Internet Explorer.
An Internet Service Provider is used to gain access to the Internet.
e.g Eircom, Esat, Indigo
Creating websites
HTML Editors
There are two choices:
- Text based
- Require a knowledge of HTML
- MS Notepad
- WYSIWYG
- Automated website construction
- Macromedia Dreamweaver and MS Frontpage
In the creation of this website I have used the following languages:
HTML (HyperText Markup Language)
HTML is not a procedural language like C, Pascal or Fortran but a Markup Language.
This means it identifies elements of a page so that a browser can generate that page on your
screen. It is used to format text and information. It uses tags (keywords contained in pairs of
angle brackets) in the creation of webpages.
Javascript
Javascript is a scripting language i.e it facilitates a disciplined approach to web
design. It enhances the functionality and appearance of web pages..."it brings them to life"
[Back to Top]
|