There are different types of cookies. There are cookies that last until you quit your web browser. These cookies are discarded once you quit your browser. Another type of cookies is what is called a persistent cookie. These persistent cookies have a "sell by" date on it. What this means is that these cookies last for a specified amount of time and then will be destroyed after the given date (3). The main difference between the two is the temporal difference - persistent cookies generally last longer than regular cookies.

The information in cookies can tell a lot about a user's preferences and habits on the Internet. Cookies can store information that contains things spanning from what kind of products you buy, to how many times you have visited a particular web site (4). For example, a user can visit www.weather.com and put in College park's zip code to get the weather daily. Later on in the week, that user can go to the site, and it will automatically take the user to College Park's weather without putting in his or her zip code.

With cookies being able to store bits of information about a user's preferences, people can get worried and think that cookies can store all types of information like passwords and credit card numbers. People think that cookies are programs. In fact, cookies are not programs that can be turned on and off to look into the software of a computer and extract information. Because of this, a user's information is relatively safe, considering that hackers do not attack the computer.

E-commerce sites also use cookies. Different companies get partnerships with different websites. By doing this, the companies can read and write to the same cookie. In cases like this, the cookie can act like a wiretap for the Internet, or a "virtual name tag" (5). For example, a user can submit personal information to a web site (i.e. the user's name) to apply for a free download. If that site has a partnership with another company, the other company can see the information on that cookie. Because of this, when the user goes to the other companies' web site, the screen can say, "Hello" followed by the user's name. This is similar to college students receiving junk mail after fact of filling out a credit card application on campus.

Cookies are useful means for tailoring a website for custom use by any individual. This is especially useful in advertising online. Cookies are small files which act as a remembrance system for websites since each visitation session to the website is not stored in a solid state. Each connection to a website is unique and the servers that run the websites cannot distinguish one visitor from another without a means to log and track users. "Essentially, cookies make use of user-specific information transmitted by the Web server onto the user's computer so that the information might be available for later access by itself or other servers."(6) Often, websites do not have the capacity to store individualized information about every user that visits the site. This would take up a tremendous amount of disk storage, money and resources depending on how much information is stored in the cookie. Instead, what a website will do is "watch" as you browse within the site and store your preferences within a small file on your computer called a "cookie." Storing it on your computer in this format is a more efficient way of remembering users since there is only one individual file of a relatively small size containing their personal information.

The type of information stored in a cookie is controlled by each website that generates the cookie stored on your computer. Some websites would like to track a visitor and see which kinds of products he or she dislikes. This allows the websites to transform the website into a more euphoric place for the visitor. "To express this in more familiar terms, when you enter a store for the first time, a professional salesperson will greet you, ask your name, and offer to help you. When you return to the store, that same professional will remember your name, and will recall what you purchased, what you liked and didn't like, and will use that information to make your subsequent visits more enjoyable. Cookies allow web developers to create the same environment in a web application." (7)

Another way, in which cookies are used in websites, is to gather information from your perusing of the various websites without user knowledge. Usually, cookies are left on a computer without informing the user that personal information may be stored there. Websites then use these cookies to customize the banner advertisements, that are prevalent on many websites today, to your particular interests. This is done in hopes of generating business for the advertiser or revenue for the website.

One such company that is notorious for tracking the Internet browsing habits of users is Doubleclick. Doubleclick has a scheme to make money by gathering information from users, through the use of cookies, to customize the banner advertisements on websites and other direct marking initiatives. A user may not ever actually visit the Doublclick website, but may in fact find a cookie on their computer that was placed there by one of Doubleclick's partner websites. What information is being gathered is ambiguous to most users. Doubleclick doesn't disclose which information is being gathered, nor why.

A company such as Doubleclick, obtains user information through the use of cookies. When an affiliate website of Doubleclick receives a request from a user without a cookie, a request is made to Doubleclick for a cookie and it is then placed within the user's computer. User information is then tracked, such as visited websites. With the banner advertisements and cookies, web content can be customized specifically for the interests of the user through, gender, race, ethnicity, or income among other things. A male user visiting www.somesite.com, may find banner advertisements for "power tools" or "male only" goods, whereas a female visitor to the same website, may see advertisements for "makeup" or other "feminine" products. This information can be displayed just by knowing the interests and tastes of the individual user who visits the website.