Cookies are small files stored on your computer. They are sent by a web server, for example. After visiting some pages. Most often they are used to facilitate and automate the operation site. The contents of cookies does not allow for identification of the user. Cookies typically contain the name of the website from which time store on your hard disk, and a unique number.
Cookies are used to store small user data, allowing you to automatically login, save the contents of the basket in the online shop or preferences or system, and the language of the site. Sometimes they are part of the counters of visits, probes and anonymous statistics, in order to check whether the user of the computer has already been counted by the counter or voted in the poll.
To block cookies or prevent some features, you change the settings of your web browser.