Cookies [http://en.wikipedia.org/wiki/HTTP_cookie] are small text messages which are stored on on-line devices (typically your computer) when a device accesses the internet. A cookie enables a web page to recognize a user it encountered before, and store information to either personalize a service or optimize site performance.
A cookie can be set to expire just after the user is done with the website or it can stored for a longer time one your online device. An example of the former is when cookies are used in navigation, examples of the latter are for storing user preferences, or in analyses of user behaviour or traffic.
Most web browsers automatically accept cookies. As a user you however have the possibility of accepting or rejecting a cookie, by changing the settings in your browser. Note that removing cookies may log you out or change website behaviour. If this behaviour is important to you, you can usually restored it by unblock the site from the browser cookie list.
Below is a list of advice on how to disable cookie in the most common browsers:
In Chrome you should go to settings under “Customize and control Chrome” (the wrench). Click “Settings” in the menu, then “Show advanced settings” (at button) then “Privacy”, “Contents settings…” and then you will be able to block all cookies or just the cookies from this site.
In Firefox go to “Tools” in the top-menu. Click “Options”, then the tab, “Privacy”. Under the label “History” you should choose “Use custom settings for history” to set your preferences in relation to cookies. Within the History context you will also find two handy links to clear your “recent history” or “delete individual cookies”.
In Safari you should visit the “Safari” menu item, press “Preferences”. Then you should go to “Privacy” and you can either “Remove All Website Data” or change the cookie settings in the “Block“ section to the way you like them.
In Internet Explorer 8 go to Tools, choose Internet Options, then choose the “Privacy” tab. Now you should either press the button “Sites” or “Advanced”, and you will be allowed to either “Block or allow all cookies”, “Block or allow cookies based on their type” or “Block or allow cookies from specific websites”.
If you are using other browsers, you will probably find similar functionality, by looking in the help menu.