Whenever a computer user accesses the world wide web, the user's computer and the computer from which it is seeking information must "talk" to each other. The world wide web uses a standard language to accomplish this conversation, called HTML (Hypertext Markup Language), and in this way all computers connected to the web can understand each other and exchange information. Your browser, the program which you use to access the internet, and the web server, the computer containing the information you are looking for, talk to each other using HTML.

Cookies are data files contained in the HTML code flowing back and forth between a user's computer and a web server. When a user establishes an internet connection to a web server, that server automatically stores a cookie on the user's computer in a file called a cookie list. When the user returns to the web page server that installed the cookie, the cookie is retransmitted, this time from the user's computer to the web server. All of this takes place automatically, and the user would have no idea from the computer screen that cookies are flowing back and forth.

The purpose of cookies are to facilitate the flow of information between the user's computer and the web server. This can allow for faster loading of web pages when a user returns to a site, or it can be used to store information about the user which benefits the user when he or she returns. For example, you may be able to personalize a web page so that it will track the price of stocks you select, or you can select items during online shopping and the server will be able to keep track of all the items you want to purchase.

Cookies are data files, they contain only information that the web server supplies or the user supplies, they do not have the ability to infiltrate a computer's hard drive and carry away information to the web server.

However, cookies do raise some privacy concerns. If web browser's collect data on cookies and combine that information with personal information about a person, such as a name and address which might be supplied in order to register with a website, then that information could be combined with information from other web browsers and used to build a personal profile of the user.