Download The Internet and the World Wide Web Basics

The Internet and the World Wide Web Basics
The internet was originally created as a means of redundant
communication links between many places without disruption of service should
one site have been taken out by nuclear attack. All sites are connected to all
other sites and talk to specific systems through protocols. The fundamental
reason the World Wide Web was created was to provide a way to view
information other than just text. However, when the web was initially created the
speed and volume of communication was very limited. The limited bandwidth
spawned the idea of a mark up language that instead of sending large amounts
of formatted data, the description of the data would be sent in a standard ASCII
file and a secondary program would produce the final presentation and link the
documents to other relevant material. This was the birth of hypertext markup
language (HTML). This section will show the basic working principles of the web
to effectively maintain your website. This knowledge is absolutely necessary to
understand and will help to speed the update and resolution of problems.
The Global Network
The Internet is a global network of computers linked together through a
communications infrastructure. It is far bigger than just the World Wide Web even
though the web is the highest usage to the average person.
The important thing to remember in working on the internet is the origins.
All current technology is based on the fundamentals of this original network of
linked military and academic institutions. The infrastructure, standards and
conventions, and protocols make the system work in a modular fashion. There is
no great supercomputer or core database that controls the internet. The main
controlling factors are the limited governing bodies that administrate the network
itself.
Physical Infrastructure and Protocols
The internet at the basic level is no more sophisticated than a small office
network. The internet was created and lives dynamically in the UNIX
environment. The original net ARPNET were mainframe UNIX computers linked
together over ordinary phone lines. As an early internet user a person would
connect as if it were a UNIX terminal. In making this connection a person would
then be connected to all of the mainframes on the net. The infrastructure today
has so much traffic that higher bandwidth connections are in place. These are
called the internet backbones. There a several to maintain the redundant
capabilities of the network. Because one system will have multiple connections to
others a physical “Web” of connections is made. The World Wide Web is a
description of this network phenomenon and is the most common use. Figure (1)
shows how the connections are made and Figure (2) shows how they are
typically referred to.
Toronto
Ottawa
Vancouver
Home
#2
Home
#1
New York
Los Angeles
Figure 1 - Basic Connectivity
Toronto
Ottawa
Vancouver
Home #
1
Los Angeles
New York
Figure 2 - Network Diagram of the Internet
What allows all of this to work is the use of the Transmission Control
Protocol/Internet Protocol (TCP/IP) protocol. Each system on the network must
have a unique internet address. Every web server, every home or office user
and every device that is connected to the network has its own address. When
two systems are communicating what they will do is to send the information
everywhere at the same time. If you look at figure 1 you can see a multitude of
paths from Home #1 to Home #2. The complexity of all the connection reduces to
the cloud shown in figure 2. The combination of address and the TCP/IP protocol
to almost guaranteed transmission success. Most problems therefore occur in
the main single connections from the home to the Internet service provider. The
website would be located in the equivalent of Toronto on the Bell Nexxia servers
as you can see they are well connected.
If you think of all the people on the internet sending and receiving
information at the same time to everywhere it would get extremely congested. In
Home
#2
fact some viruses attempt to do this. The combination of technologies such as
bridges and routers act as the traffic control systems by directing the information
in the direction it needs to go and blocking from where it doesn’t need to go.
More information on this is available but is not necessary for the purposes of this
course. The other major controlling technology on the web is databases. You
might be surprised at how many you use without even knowing. All are located
on the servers that make up the internet.
Web Servers
The web server is the main host for the website. Hosting simply means
your files are honored guests on the web server connected to the internet. The
website is located at an Internet Protocol address like 198.13.78.256. That is
hard to remember let alone having someone else try to remember. If you were to
put in the number it would work however www.yourwebsite.com uses the
combination of Universal Resource Locator (URL) and Domain Name Service
(DNS). They run on the power of UNIX databases.
Universal Resource Locators and Domain Name Service Servers
www.website.com is a URL. When a user types this into a browser and
clicks go, the URL is sent to the nearest DNS server where the database is
queried for the IP address. Because of the nature of the internet itself there are
literally thousands of DNS server databases around the world to allow the use of
URLs. This system works because each user has a unique IP address. The IP
address is looked up in what is called the WHOIS database which you might be
familiar with from office networking. When the site is registered as an internet
domain all of the servers around the world must synchronize the information.
This process usually takes approximately twenty four hours. The number of DNS
servers explains why people in Paraguay may be able to access the site while
people in Portugal cannot since it has not reached their DNS servers.
One of the advantages of this technology is that you can find out who is
looking at your site. Most hosting services log the IP address of the users that
request information from the Site. The WHOIS databases provide information for
demographic reporting on the visitors to the site. For example a former Radio
Tracking company’s website produced reports from Australia Post, New Holland
Tractors and the US Military as well as others. It provided the sales team with the
information of who is interested in the product or service. This could be valuable
in targeting new groups of prospects for the company simply by printing the
report. There are also many security features to this but that is beyond the scope
of this manual.
Search Engines
Search engines are simply online databases. They store all of the key
information for a site. The user simply queries the database for like criteria. The
database then displays the information matching the criteria in alpha numerical
order. This being known, a few people realize that if they start there entry with a
1 or A such as #1 Investment Counseling they have the greatest chance at being
at the top of the list displayed. Yahoo and Google are currently the most widely
used and work on this principle. Some other engines such as Lycos and
WebCrawler use what are called robots or AI (artificial intelligence). It sounds
complicated but what they are doing is actively searching the WHOIS databases
on the DNS Server and recording into a database what is found on the site. The
program isolates key words from Meta data on web pages and this is the
information that the queries are done on. The program is far from perfect and
most people prefer the results from the manually entered databases.