Cookie
Cookies. Cookies. Certain information which registers from the site visited by you in your computer. When you visit again the website which wrote cookie on your computer, the website "recognizes" you (it can be expressed that you will not need to become authorized on the website, let us assume, if it is any forum, authorization in this case will be automatic, but "recognition" consists not only in it, cookie allows to define whether there were you on this website if yes, that when how often you are on the website from what IP addresses you came, etc. - these data are used for statistics of this website). You can turn off support of cookie in your browser and to become "invisible" to similar statistics ("recognition"), however seldom use it for the reason that some websites can refuse to you issue of information if your cookie are disconnected.
2021: The announcement of Federated Learning of Cohorts (FLoC) - technology for replacement of cookie files
At the end of January, 2021 Google told about the Federated Learning of Cohorts (FLoC) technology developed by the company which, according to her, can replace cookie files. Based on tests, FLoC provides more high efficiency of advertizing, developers claim. Read more here.