A cookie is a piece of information in the form of a very small text file that is placed on an internet user's hard drive. It is generated by a web page server, which is basically the computer that operates a web site. The information the cookie contains is set by the server and it can be used by that server whenever the user visits the site. A cookie can be thought of as an internet user's identification card, which tell a web site when the user has returned.
When you log into WordPress, WordPress stores the following two cookies:
The cookies are set to expire two weeks from the time they are set.
When you write a comment, Three cookies are set for to make it easy for you to write another comment:
The commenter cookies are set to expire a little under one year from the time they're set.
For more information on WordPress cookies please see the below link:http://codex.wordpress.org/WordPress_Cookies
|__utma||This cookie is typically written to the browser upon the first visit to your site from that web browser. If the cookie has been deleted by the browser operator, and the browser subsequently visits your site, a new __utma cookie is written with a different unique ID. This cookie is used to determine unique visitors to your site and it is updated with each page view. Additionally, this cookie is provided with a unique ID that Google Analytics uses to ensure both the validity and accessibility of the cookie as an extra security measure.||2 years from set/update.|
|__utmb||This cookie is used to establish and continue a user session with your site. When a user views a page on your site, the Google Analytics code attempts to update this cookie. If it does not find the cookie, a new one is written and a new session is established. Each time a user visits a different page on your site, this cookie is updated to expire in 30 minutes, thus continuing a single session for as long as user activity continues within 30-minute intervals. This cookie expires when a user pauses on a page on your site for longer than 30 minutes. You can modify the default length of a user session with the _setSessionCookieTimeout() method.||30 minutes from set/update.|
|__utmc||Description: This cookie is no longer used by the ga.js tracking code to determine session status. Historically, this cookie operated in conjunction with the __utmb cookie to determine whether or not to establish a new session for the user. For backwards compatibility purposes with sites still using the urchin.js tracking code, this cookie will continue to be written and will expire when the user exits the browser. However, if you are debugging your site tracking and you use the ga.js tracking code, you should not interpret the existence of this cookie in relation to a new or expired session.||Not set.|
|__utmz||Description: This cookie stores the type of referral used by the visitor to reach your site, whether via a direct method, a referring link, a website search, or a campaign such as an ad or an email link. It is used to calculate search engine traffic, ad campaigns and page navigation within your own site. The cookie is updated with each page view to your site.||6 months from set/update.|
|__utmv||Description: This cookie is not normally present in a default configuration of the tracking code. The __utmv cookie passes the information provided via the _setVar() method, which you use to create a custom user segment. This string is then passed to the Analytics servers in the GIF request URL via the utmcc parameter. This cookie is only written if you have added the _setVar() method for the tracking code on your website page.||2 years from set/update.|
|__utmx||This cookie is used by Website Optimizer and only set when the Website Optimizer tracking code is installed and correctly configured for your pages. When the optimizer script executes, this cookie stores the variation this visitor is assigned to for each experiment, so the visitor has a consistent experience on your site. See the Website Optimizer Help Center for more information.||2 years from set/update.|
For more information on Google Analytics cookies please see the below link:https://developers.google.com/analytics/resources/concepts/gaConceptsCookies