It allows that site to store information and later come back and retrieve that information.
It identifies you and when you come back to that site again the Web page knows that you have been there before and can track that.
It remembers names and passwords and automatically log you into that web site again.
For example, when you go to a site and order something normally you have to choose a user name and password.
Once you do that if you go back there again the web site will likely remember when you go back and automatically fill your information in for you.
The web site can only retrieve information that it put on your computer, not information that any other site put there.
Many people have believed that cookies are in the same class as spyware and adware.
They feel that they are not harmful to your computer but make surfing the web much easier.
They also feel that cookies collect information about visitors to the site.
Many people feel that cookies are programs that sit on your computer and gather information about where you go on the Internet and that it can download all that information any time that it wants to.
But actually they are not programs and they can only retrieve information that they put on your computer not anything that was put there by anything else.
Mostly the cookies help the Web site determine how many new visitors were on the site versus how many repeat visitors were on the site.
It assigns each visitor a unique ID to help keep track of this.
Also, if you have purchased something on a site, the next time that you come to that site, if you were to purchase something again, it will be easier.
It will be easier because the information could all be filled in the next time because of the cookies and the information that they can fill out for you all ready.
The little padlock that you can see at the bottom of the tool bar when you are at a web site indicates that the site is a secure one.
If you begin having problems and call for help, the first thing that they will have you do is to erase all your temporary Internet files.
Often, this can actually solve a lot of your problems.
When buying something from a company there can be a drawback.
The company can sell your information to another company, and that is how junk mail comes about.
This also can happen when ordering something through the mail or over the phone as well.
There are sites that have different privacy policies though and if you read the fine print you may be able to check a box asking them to not sell your information to anyone else.
It is important to be very careful when ordering anything to be sure to read the fine print.
You may not want to order from anyone who does not guarantee you that they will not sell your name to others.