A cookie, also known as an HTTP cookie, web cookie, or browser
cookie, is a small piece of data sent from a website and stored
in a user's web browser while a user is browsing a website. When
the user browses the same website in the future, the data stored
in the cookie can be retrieved by the website to notify the
website of the user's previous activity. Cookies were designed
to be a reliable mechanism for websites to remember the state of
the website or activity the user had taken in the past. This can
include clicking particular buttons, logging in, or a record of
which pages were visited by the user even months or years ago.
Although cookies cannot carry viruses, and cannot install
malware on the host computer, tracking cookies and especially
third-party tracking cookies are commonly used as ways to
compile long-term records of individuals' browsing histories — a
major privacy concern that prompted European and US law makers
to take action in 2011. Cookies can also store passwords and
forms a user has pre