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 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.
(Information taken from

The cookies we use are as follows:
Cookie/s Name: __utma, __utmb, __utmc, __utmz
Description – Google Analytics: Tracking the path of visitors through the website and identifying returning visitors. Statistics derived from this information help us identify how well certain pages and aspects of the site perform, and where we can make improvements to help visitors access the information they need more quickly and with less hassle.
Expiry: From 30 minutes to up to 1 year