A cookie is a small, often encrypted, text file, which is created on your device when you visit a website that uses cookies. This file is stored on your device's hard drive, and is read by your web browser. Contrary to what many people may believe, this file is not a virus and it cannot harm your computer.

Cookies are used to perform a variety of functions. These can be categorised as below.

Strictly necessary cookies These cookies are essential in order to enable you to move around the website and use its features, such as accessing secure areas of the website. Without these cookies services you have asked for, like shopping baskets or e-billing, cannot be provided.

Performance cookies These cookies collect information about how you use a website and report any error messages from relevant webpages. For example website owners will use performance cookies to follow which webpages you’ve read to determine which parts of a website are most engaging. Information collected using these cookies is aggregated and therefore anonymous. In general, these cookies are used to help improve how a website works from both a user and technical perspective.

Functionality cookies These cookies allow websites to remember choices you make (for example, your user name, language or the region you are in) and provide enhanced, more personal features such as local weather reports. These cookies can also be used to remember changes you have made to text size, fonts and other parts of webpages that you can customise. They may also be used to provide services you have asked for such as watching a video. The information these cookies collect may be anonymised and they cannot track your browsing activity on other websites.

Targeting or Advertising Cookies These cookies are used to deliver adverts more relevant to you and your interests. They are also used to limit the number of times you see an advertisement as well as help measure the effectiveness of advertising campaigns. They are usually placed by advertising networks with the website owner’s permission. They remember that you have visited a website and this information is shared with other organisations such as advertisers. Quite often targeting or advertising cookies will be linked to website functionality provided by the other organisation.

Depending on their use, cookies can last for different lengths of time.

Session cookies are created temporarily and are only stored for as long as you browse the website. They expire as soon as you leave the website or when you close your web browser.

Persistent cookies remain on your device for a fixed period of time which is defined within the cookie. This allows the website to recognise your device again when you return to that website from your device.

First party cookies are set by the website that you are visiting and can only be read by that website.

Third party cookies are set by an entity other than the owner of the website. This might be for the purposes of advertising, website measurement, or being able to watch a video on the website.

Adobe uses a particular type of cookie called a ‘Local Shared Object’, which is typically collected if you watch a video for example that uses the Adobe Flash media player, i.e. an embedded YouTube video on a page that is being played via Flash. Please note that these types of cookie will not be found on iPads, which do not support Flash. Have a look at Adobe's website if you want to control Flash cookies on your device. If you’ve got a Firefox browser you can also get an add-on to detect and delete Flash cookies.

Web beacons, sometimes referred to as ‘web bugs’, are small single-pixel transparent image files. They allow website owners to know when a visitor has reached their website and are used in conjunction with cookies to allow further website tracking. These files are not viruses and are useful in helping website owners to make your web-browsing experience better.