In general, cookies are used to retain user preferences, store information for things like shopping carts and provide anonymised tracking data to third party applications like Google Analytics.
There are cookies that are stored in your device only for the time of visit and are removed once you left site, as well as ones stored longer (you may delete them at any given moment, of course). Cookies consist of a string of letters and numbers that can be read only by the server that created it, and are used to recognize unique visitor and therefore provide settings and services expected by the user. Cookies do not discover your identity nor sensitive data, though. It’s job is to inform server that you already visited the site and, for example, preferred to display it in different language.
As a rule, cookies will make your browsing experience better. However, you may prefer to disable cookies on this site and on others. The most effective way to do this is to disable cookies in your browser. Please consult the Help section of your browser or take a look at the About Cookies website which offers guidance for all modern browsers.