A cookie is a text file filed, subject to your choices, on your computer when visiting a site or consulting an advertisement. Its purpose is to collect information relating to your navigation and to address you services adapted to your terminal (computer, mobile or tablet).
Cookies are managed by your Internet browser and only the sender of a cookie is likely to read or modify the information contained therein.
How to exercise your choices, according to your browser?
For the management of cookies and your choices, the configuration of each browser is different. It is described in the help menu of your browser, which will allow you to know how to modify your wishes with regard to cookies.
For Internet Explorer™ : https://support.microsoft.com/en-us/help/17442/windows-internet-explorer-delete-manage-cookies,
For Safari™ : https://support.apple.com/?path=Safari/3.0/en/9277.html,
For Chrome™ : https://support.google.com/chrome/answer/95647?hl=en&hlrm=en,
For Firefox™ : https://support.mozilla.org/t5/Firefox/ct-p/Firefox,
For Opera™ : http://help.opera.com/Windows/10.20/en/cookies.html