http://i3bpnmxqgp5e7z5gvpkz53y3pwyyk72yevshfutyseb4bzqh2lgucpad.onion/blog/browser-cookies-what-are-they-why-should-you-care.html
What Goes Into a Cookie? Cookies associate bits of data to a specific user. For example, if you visit a website, the site may deliver a cookie identifying you as user X. If you leave the site and then return to it again, that cookie will be used by the website to recognize that you are the same user X that was at the site previously.