A "cookie" is a small piece of information sent by a web server to store on a web browser so it can later be read back from that browser. This is useful for having the browser remember some specific information and saves time. </p>
We use Session Cookies in the following manner:
;A Session Cookie is a line of text that is stored temporarily in your computer’s random access memory (RAM). A session cookie is destroyed as soon as you close your browser. Log-on and log-off process – you do not have to log-on and register to browse our site. If you decide to register with our site to use one of our online services, session cookies help with the log-on and log-off process. The cookies enable us to recognize your log-on ID when you log on so that we do not create a duplicate registration record for you. Transactions and site usability – we use Session Cookies to improve how you navigate through our Web site and conduct transactions. Session Cookies are used to maintain your online session as you browse over several pages, or to store and enter information on a Web page so that you do not have to reenter the same information, repetitively. Session Cookies may also be used to collect referral statistics when you click on a link.
Like many services, Google Analytics uses first-party cookies to track visitor interactions. These cookies are used to store information, such as what time the current visit occurred, whether the visitor has been to the site before, and what site referred the visitor to the web page. Browsers do not share first-party cookies across domains.
To provide website visitors with more choice on how their data is collected by Google Analytics, Google have developed the Google Analytics Opt-out Browser Add-on. The add-on communicates with the Google Analytics JavaScript (ga.js) to indicate that information about the website visit should not be sent to Google Analytics. If you want to opt out, download and install the add-on for your current web browser. The Google Analytics Opt-out Browser Add-on is available for Internet Explorer, Google Chrome, Mozilla Firefox, Apple Safari and Opera.
http://windows7themes.net/how-to-enabledisable-cookies-in-internet-explorer-9.html
https://support.google.com/chrome/bin/answer.py?hl=en&answer=95647&p=cpn_cookies
http://support.mozilla.org/en-US/kb/Enabling%20and%20disabling%20cookies