Cookies
A cookie is a computer text file sent
to a visitor's Web browser (the software used to access the Internet such as
Internet Explorer and Netscape) by a Web server (the computer that hosts the
Web site) in order to remember certain pieces of information. This can be a
convenience for both Web site visitors and operators because it can be used to
reduce the amount of time to input and process the same information each time a
Web site is used.
Information stored within a cookie can
be read only by the Web server that originally sent the cookie, not by other
Web servers.
Typically, a cookie comprises:
1. a name for
the cookie (chosen by the Web site you are visiting)
2. a value
(unique number for the cookie) (determined by and stored by the Web site for
future recognition and action)
3. an expiration
date
4. a valid path
(details about the Web page(s) that the visitor was on when the cookie was
sent)
5. a valid
domain (the name of the Web site that created and can retrieve the cookie)
6. a secure
connection requirement (if the cookie is marked "secure", it will
only be transmitted if the visitor is connected to a secure Web site
There are two types of cookies.
Session Cookies: These
cookies reside on the Web browser and have no expiry date. They expire as soon
as the visitor closes the Web browser. Session cookies remember information
only for as long as the visitor operates the Web browser in a single
"session" (or "sitting"). Session cookies can be used by
Web site operators to determine information such as what parts of a Web site
are popular, how long people stay on certain sections of a Web site and what
browsers people are using.
Persistent Cookies: These
cookies have an expiry date, are stored on a visitor's hard drive and are read
by the visitor's browser each time the visitor visits the Web site that sent
the cookie. It is possible for the Web site that created the cookie to extend
the expiry date without notice to the visitor. They will remain there until the
set date has expired or until the visitor has deleted the file. However, most
people do not know how to delete cookies. In addition, the prolonged existence
of persistent cookies means they can be used to follow Web browsing behaviour
and purchasing habits. In some cases, they can also be used to identify a Web
visitor when the persistent cookie data is combined with information from other
sources such as databases (for example, matching an IP address with
a person's name).
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