A cookie is a small text file that a website saves on your computer or mobile device when you visit the site. It enables the website to remember your actions and preferences (such as login, language, font size and other display preferences) over a period of time, so you don’t have to keep re-entering them whenever you come back to the site or browse from one page to another.

A number of our pages use cookies to remember:

• your display preferences, such as contrast colour settings or font size
• if you have already replied to a survey pop-up that asks you if the content was helpful or not (so you won't be asked again)
• if you have agreed (or not) to our use of cookies on this site

Also, some videos embedded in our pages use a cookie to anonymously gather statistics on how you got there and what videos you visited.

Enabling these cookies is not strictly necessary for the website to work but it will provide you with a better browsing experience. You can delete or block these cookies, but if you do that some features of this site may not work as intended.