Cookies are browser-specific. A cookie set when you browse in Netscape Navigator will not be read if you visit the same site again using Internet Explorer. Cookies cannot store any personal information about the user that the user doesn't voluntarily supply to the Web site. Cookies do not contain viruses. A server can only get data from the cookie it wrote to the cookie file - it can't go fishing for information on the hard drive.
Links take the user to a personalized page that highlights products based on their personal profile.
Useful Applications For Cookies Web sites use cookies for a number of different reasons. Site Personalization - As in the Amazon example above, you can use cookies to identify visitors and direct them to areas of you site that might interest them most. Sites can use session cookies that are valid only for the duration of that particular visit, or design them so that the user can return to the site days later and complete their transaction. Web site Tracking - Cookies provide you with a more accurate count of site visitors. Using cookies, you can insure that someone who visits your site 3 times per day isn't counted as a unique user each time.