An HTTP Cookie is a small piece of data sent from a website and stored in the user's web Browser while the user is browsing. cookie s were designed to be a reliable mechanism for websites to remember stateful information or to record the user's browsing activity. they can also be used to remember arbitrate pieces of information that the user previously entered into from fields such as names, addresses, passwords, and credit card numbers.
other kind of cookies perform essential functions in the modern web. perhaps most importantly, authentication cookies are the most common method used by web servers to know whether the user is logged in or not, and which account they are logged in with. without such a mechanism, the site would not know whether to sent a page containing sensitive information, or require the user to authenticate themselves by logging in. the security of an authentication cookies generally depends on the security of the issuing website and he user's web browser, and on whether the cookie data is encrypted.
