On this website we use both persistent and session cookies

What is a cookie?

A cookie is a small text file which the website you’re visiting requests to save on your computer. Cookies are used on many websites to give users access to different functions. The information in the cookie can also be used to monitor your use of different websites which use the same cookie.
There are two types of cookie. One type saves a file on your computer for a long time and has an expiry date. It is used for functions such as letting you know what’s new since your last visit to the website. Once the expiry date has passed, the cookie is deleted automatically when you return to the website that created it. 

The other type of cookie is called a session cookie and has no expiry date. While you are visiting a website, this type of cookie is temporarily stored in your computer’s memory, for instance to remember which language you have chosen. Session cookies are not stored on your computer for a long time, but are always removed when you close your web browser.