A cookie is a small text file that contains data. It is placed by a website onto your computer when you access the website.
If you do not want to accept cookies, you can adjust the settings in your web browser's security preferences so that you either do not accept any cookies at all or so that your consent is requested every time a website tries to put a cookie on your computer. You can also delete cookies that have previously been stored in your web browser; see the web browser's help files for more information.
The Swedish Post and Telecom Agency, which is the relevant supervisory agency, has additional information about cookies on its website: http://www.pts.se/en-GB/Industry/Regulations/Legislation/Electronic-Comm...