A piece of state information supplied by a Web server to a browser, in a response for a requested resource, for the browser to store temporarily and return to the server on any subsequent visits or requests.
Sources:
CNSSI 4009-2015
NIST SP 800-28 Version 2
under Cookie
A piece of state information supplied by a web server to a browser that is temporarily stored and returned to the server on any subsequent visits or requests.
Sources:
NIST IR 8459