Internet Research

Structure of the Internet

Understanding the

Even long-time computer users do not understand the fundamental structure and concepts underlying the Internet and World Wide Web.

But Internet research is enhanced with even a basic understanding of an apparent alphabet soup, such as http, URL, IP, .com, www and others.

The Internet is a network

The Internet is a network of thousands of connected computer networks around the world.

Networks, clients & servers

Computer networks are built upon client-server relationships.

Simply, the client requests information or a file. The server stores information and responds to requests for information.

A Client Request

Your personal computer software is a client.

For example, when you linked to a class web site: Your client software made a request of the university server that stored and sent you the web site.

You don’t go to the web site. The server sends the web site to you.

Client software: The browser

The client software used to make requests of servers, and then display the response to those requests, is called a browser.

The most common Web browsers are Netscape Communicator (previously Navigator) and Microsoft Internet Explorer.

Others include Opera and Lynx.

IP

How do browsers find the file you want? Like the mailman, they go to a specific address.

Every computer connected to the Internet has been assigned an Internet Protocol number. A Protocol is the rules by which different computers can communicate and transfer files.

URL: an address

Usually this long string of numbers is in four parts, separated by dots: 323.556.123.8

But who can remember such numbers? The computer and its number thus are also given a name (an alias) that can serve as an address.

Clients and servers request, identify and send files on the Web using these names in the Uniform (or Universal) Resource Locator: URL.

http://www.lehigh.edu

The URL tells you where the information can be found and how to access the information.

For example, the URL for Lehigh University is: http://www.lehigh.edu

http: the protocol

Most Web addresses begin with http://. This is the protocol, the rules by which different computers can communicate on the Web.

Most information on the Web uses the Hypertext Transfer Protocol: http.

The protocol comes first in a Web address so the computers know what kind of “language they should speak together.”

www.host

After the protocol comes three separation marks ://

Then comes the name of the “host” computer. Often the host is the server computer linked directly to the World Wide Web from which you are requesting information.

www.old

www was used in the early days of the Internet to tell people that the site was on the Web.

Now with most information on the Web, the www is mostly a tradition. Many web sites can be reached without even typing the www.

Master of your domain

To help further identify information, the URL follows the host with a “domain” name.

Domains further organize information, according to the type of organization or the name of a country.

.com

.com is a commercial or business site

.org is a non-profit organization

.gov is a government site

.mil is a military site

.ca is a site in Canada

.jp is a site in Japan

Home page

If you only specify a name and domain, you will likely receive the host site’s home page from the server.

If you want to access other information on that computer, you will use the usual “path” and “file name” format used by computers.

Slash

///////

You will reach information on the computer by typing a slash, then giving a directory or folder name, and perhaps another slash, with another folder’s name.

For example, http://www.wired.com/news/today

Finding the file

It’s good to remember exactly what you are doing.

From your computer, you are finding, requesting, receiving and opening a file that was saved on someone else’s computer perhaps halfway around the world.

That is Internet research.


	Even long-time computer users do not understand the fundamental structure and concepts underlying the Internet and World Wide Web.
	But Internet research is enhanced with even a basic understanding of an apparent alphabet soup, such as http, URL, IP, .com, www and others.


	The Internet is a network of thousands of connected computer networks around the world.


	Computer networks are built upon client-server relationships.
	Simply, the client requests information or a file. The server stores information and responds to requests for information.


	Your personal computer software is a client.
	For example, when you linked to a class web site: Your client software made a request of the university server that stored and sent you the web site.
	You don’t go to the web site. The server sends the web site to you.


	The client software used to make requests of servers, and then display the response to those requests, is called a browser.
	The most common Web browsers are Netscape Communicator (previously Navigator) and Microsoft Internet Explorer.
	Others include Opera and Lynx.


	How do browsers find the file you want? Like the mailman, they go to a specific address.
	Every computer connected to the Internet has been assigned an Internet Protocol number. A Protocol is the rules by which different computers can communicate and transfer files.


	Usually this long string of numbers is in four parts, separated by dots: 323.556.123.8
	But who can remember such numbers? The computer and its number thus are also given a name (an alias) that can serve as an address.
	Clients and servers request, identify and send files on the Web using these names in the Uniform (or Universal) Resource Locator: URL.


	The URL tells you where the information can be found and how to access the information.
	For example, the URL for Lehigh University is: http://www.lehigh.edu


	Most Web addresses begin with http://. This is the protocol, the rules by which different computers can communicate on the Web.
	Most information on the Web uses the Hypertext Transfer Protocol: http.
	The protocol comes first in a Web address so the computers know what kind of “language they should speak together.”


	After the protocol comes three separation marks ://
	Then comes the name of the “host” computer. Often the host is the server computer linked directly to the World Wide Web from which you are requesting information.


	www was used in the early days of the Internet to tell people that the site was on the Web.
	Now with most information on the Web, the www is mostly a tradition. Many web sites can be reached without even typing the www.


	To help further identify information, the URL follows the host with a “domain” name.
	Domains further organize information, according to the type of organization or the name of a country.


	.com is a commercial or business site
	.org is a non-profit organization
	.gov is a government site
	.mil is a military site
	.ca is a site in Canada
	.jp is a site in Japan


	If you only specify a name and domain, you will likely receive the host site’s home page from the server.
	If you want to access other information on that computer, you will use the usual “path” and “file name” format used by computers.


	///////
	You will reach information on the computer by typing a slash, then giving a directory or folder name, and perhaps another slash, with another folder’s name.
	For example, http://www.wired.com/news/today


	It’s good to remember exactly what you are doing.
	From your computer, you are finding, requesting, receiving and opening a file that was saved on someone else’s computer perhaps halfway around the world.
	That is Internet research.