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 tells a website when the user has returned.
Google Analytics sets cookies to help us accurately estimate the number of visitors to the website and volumes of usage. We use this data to improve our website and online services.
What is the purpose of using 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.
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, modern versions of both Microsoft Internet Explorer and Netscape browsers 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. 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.
Controlling and deleting cookies
You can set your web browser to accept or reject cookies, or tell you when a cookie is being sent. You can also delete cookies from your computer. But note, some websites may not work properly with the cookie option turned off.
Information Commissioner's Office [ICO] - Cookies and similar technologies