What is a cookie?
A cookie is a small file of letters and numbers downloaded on to a user device (for example a PC or a smartphone) when you access some websites. Cookies allow a website to recognise your device, each time you visit.
How do cookies work?
A website's cookies store information on your device. The information is then sent back to that website each time you visit. Sometimes this information is essential to enable you to access a website's functions - for example if you need to log in, a cookie will allow the website to recognise your log in details. Or, if you are shopping online, a cookie will store your order information; for example, the contents of your shopping cart, so that you can make purchases.
Cookies can also be used to build a profile of your activity on a website; for example, which pages you visit, and how long you spend on each page. A website may then use this information to tailor the pages that you see when you visit the site in the future.
Do websites need permission to do this?
Yes they do. The regulations which set out the rules on this changed on 26 May 2011. Before that date, websites which used cookies had to tell you and give you the change to opt out if you objected. From 26 May 2011, websites must now get your active consent. In other words, it used to be the case that cookies were permitted unless you objected. Now, cookies are not permitted unless you agree to them.
The regulations, known as the Privacy and Electronic Communications Regulations, are enforced by The UK Information Commissioner.
Can I control or delete cookies?
All recent versions of popular browsers (e.g. Internet Explorer, Google Chrome, Mozilla Firefox, and Safari) allow you to control cookies. Typically, you can set your browser to accept or reject all, or certain cookies. You might, for example, be happy to accept a cookie that allows you to log in to a website, but prefer to reject any which are used to build a profile of your internet usage. You should also be able to set your browser to prompt you each time a cookie is offered. For detailed instructions on how to control or delete cookies on different browsers visit aboutcookies.org