Cookies may be set by the website you are visiting (first-party cookies) or they may be set by another website that runs content on the page you are looking at (third-party cookies).
A cookie is a text file that is stored on your computer or mobile device by a website’s server and only that server will be able to retrieve or read the contents. Each cookie is unique to your web browser. It will contain some anonymous information such as a unique identifier and the site name and some digits and numbers. It allows the website to remember your preferences or what’s in your shopping basket.
Some people find the idea of a website storing information on their computer or mobile device unappealing, particularly when this information is stored and used by a third party without you knowing. This is generally quite harmless you may not, for example, want to see targeted advertising. If you prefer, it is possible to block cookies or even delete cookies that have already been set; but you need to be aware that you might lose some functions of that website.