What is a cookie?
A cookie is a piece of information in the form of a small text file that is placed on an internet user's hard drive. It is generated by a web server, which is the computer that operates a website.
The information the cookie contains is set by the server and it can be used by that server whenever the user visits the site. A cookie can be thought of as an internet user's identification card, which tell a website when the user has returned.
What is the purpose of cookies?
Cookies make the interaction between users and websites faster and easier. Without cookies, it would be very difficult for a website to allow a visitor to fill up a shopping cart or to remember the user's preferences or registration details for a future visit.
Cookies enable websites to monitor their users' web surfing habits and profile them for marketing purposes (for example, to find out which products or services they are interested in and send them targeted advertisements.)
Are cookies dangerous?
No. Cookies are small pieces of text. They are not computer programs, and they can't be executed as code. Also, they cannot be used to disseminate viruses, and modern versions of Internet Explorer and browsers such as Firefox, Safari and Opera allow users to set their own limitations to the number of cookies saved on their hard drives.
Can cookies threaten users' privacy?
Cookies are stored on the computer's hard drive. They cannot access the hard drive - so a cookie cannot read other information saved on the hard drive, or get a user's email address etc. They only contain and transfer to the server as much information as the users themselves have disclosed to a certain website.
A server cannot set a cookie for a domain that it is not a member of. In spite of this, users quite often find in their computer files cookies from websites that they have never visited. These cookies are usually set by companies that sell internet advertising on behalf of other websites.
Therefore it may be possible that users' information is passed to third party websites without the users' knowledge or consent, such as information on surfing habits. This is the most common reason for people rejecting or fearing cookies.
Where can I find further information on cookies
- BBC - Webwise - What are cookies?
- Information Commissioner's Office
- Wikipedia - HTTP cookie
How do I block or remove cookiesThis external website has information on how to block cookies on the most common browsers, while details on how to remove cookies can be found onhttp://www.allaboutcookies.org.