Valid Internet Addresses

Internet Addresses

Also known as Domain names

Translate a named address (www.google.com) to a numbered IP address (74.125.45.100)

All computers on the Internet have a numbered address

IP Addresses

Every networked computer has a numbered address called an IP Address

It works like a home address and allows other computers or servers to send data to your computer

Most IP Addresses are in the following format xxx.xxx.xxx.xxx

Domain Names

When you type a domain name into the address bar, your computer looks up the IP Address that is associated with that name.

That information is held in a DNS (Domain Name Server)

If the DNS is not working properly, your computer is unable to find the correct IP Address and is not able to go to that web site.

Formatting

http://www.google.com

http is the Internet protocol that determines what your computer should do with the data. In this case, it should get the data through a web browser and display a web page

Others are: ftp:// https:// and more

http://www.google.com

www tells your computer to find the address on the World Wide Web

Sometimes, you can leave off the www and the address will still work (google.com)

http://www.google.com

The part right before the “.com” is called the root domain

In this case, Google is the root domain name

http://www.google.com

.com determines the type of site that you are visiting, although it’s not always perfectly clear.

.com was supposed to be used for businesses or company’s on the web

.what?

.net: was supposed to be for general websites, but is seldom used

.org: is used by organizations like non-profits

.edu: is used by educational institutions like colleges and schools

.gov: is used by the United States Government

Sub Domains

Subdomains are used to help keep different parts of a site separate from other parts. They may be different services that a company wants to distinguish between.

Example, http://gmail.google.com, where gmail is Google’s email service, so it has it’s own address.

Also note that the “www” is gone

What Not To Do

Internet Addresses follow simple rules:

No spaces in addresses

all letters are lowercase

periods (.) separate parts of an address

only a few special characters are allowed

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