cookies, explained

A cookie, in this context, is a small file on YOUR hard drive which
is written there by a web page. Cookies are permitted to store only a
limited amount of information, and the obstensible purpose is to let
a web page seem to 'remember' preferences, settings, etc.

There is supposed to be code in your web browser that any web site
can only read its own cookies, not cookies belonging to other sites.

Of course, the purposes to which they can actually be put are limited
only be the cleverness of computer programmers, which is pretty much
boundless.

Peter (a computer programmer, but not THAT KIND of computer
programmer)