An HTTP cookie is a small piece of data sent from a website. They are stored on the user’s computer by the user’s web browser while the user is browsing.
Cookies were designed to be a reliable mechanism for websites to remember stateful information or to record the user’s browsing activity.
Cookies can also be used to remember arbitrary pieces of information. These are things that the user previously entered into form fields such as names, addresses, passwords, and credit card numbers.