How Cookies Can Identify Web Visitors

It is possible to record many online activities including which online newsgroups or files a person has accessed, which web sites or web pages he/she has visited, which item or product that person has purchased over the web. Much of this monitoring and tracking of the web sites occurs without visitors knowledge.
                Websites can learn the identify of their visitors,

if he/she register to purchase a product or services or to obtain a free services, such as information. Web sites can also captured the information about the visitor without their knowledge by the “cookie” technology. Cookies are the tiny files deposited on a computer hard drive, when a visitor visits certain web site. Web site cookies can also identify the information about the visitor’s web browser software and track the visits to the website. When a person return to the website that has deposited a cookie on the computer hard drive and Website software will search the visitor’s computer  and will find the cookie and know what that person has done in the past. It may also update the cookie depending on the visitor’s activity during visit.

Example: If someone purchase a book on amazon.com website and return with the same browser, the site will welcome him or her by name and recommend books of interest based on his or her past purchases.