What are cookies?
A cookie is a small text file made up of numbers and letters which a website may place on your computer or mobile device when you visit the site. A cookie records basic information about your visit, such as your user settings or what pages you have viewed. The website (and potentially other websites) can then recognise this information in future and can use it to improve your overall experience, for example, by remembering your log-in details or even recommending certain content.
Types of cookie
There are different types of cookie, which perform different functions. The main types are:
- Essential cookies
- Performance cookies
Performance cookies collect information about how a website is used in order to improve the website's effectiveness. Also known as 'analytical' cookies, performance cookies track information such as, which parts of the website have been visited, what links have been clicked and if any errors have occurred. Performance cookies are commonly used to ensure that popular content is displayed more prominently on a website so that users can find the information that they are looking for more quickly.
- Functionality cookies
As the name suggests, 'functionality' cookies are used to deliver specific features or functions on a website. The most common use of functionality cookies is to remember preference settings, or to store log-in details to save you the trouble of inputting your username every time you access a site. They can also be used to deliver more complex features, such as video players that remember where a user has reached in a particular video.
- Targeting cookies
'Targeting' cookies may be placed by us, or by our advertisers, to store information about the webpages that you have viewed. This allows us and our advertisers to deliver adverts that are relevant to the content you are interested in. These adverts may be displayed on our website or on other sites that you visit.
'Targeting cookies' are also used to operate 'Like' or 'Share' buttons, which users can click to let other people know that they have found a particular webpage useful or entertaining. Other sites (normally social networking sites) will then recognise these cookies and display your shared content to other users.
How long do cookies last?
Cookies may stay on your computer or mobile device for different periods of time depending on what they are used for. Many cookies will only last for the duration of a single visit and will be automatically deleted when the browser is closed down. These cookies are known as 'session' cookies.
Some cookies are designed to stay on your computer or mobile device for a longer period and these are known as 'persistent' cookies. The length of time that a persistent cookie will stay on your hard drive depends on the purpose of the particular cookie. For more information about the cookies that we use, including how long each cookie lasts, please see the section called "Our cookies" below. You can always delete cookies (including all persistent cookies) at any time using your internet browser settings. For more information, please see the section called "Managing cookies" below.
Most modern browsers will allow you to:
- see what cookies you have got and delete them;
- block third party cookies;
- block cookies from particular sites;
- block all cookies; or
- delete all cookies when you close your browser.
Unfortunately, any preferences you select will be lost if you then delete your cookies, because it is cookies that are used to remember your preferences (ironically, this means that if you opt-out of using cookies altogether and then delete your existing cookies, your choice to opt-out will also be forgotten!).
You should be aware that if you chose to block all cookies many websites will not work properly and some features will not work at all. We do not recommend turning cookies off for this reason. If you are primarily concerned about third party cookies generated by advertisers, you can turn these off separately.
The links below take you to the ‘Help' sections for each of the major browsers so that you can find out more about how to manage your cookies.
For more detail about cookies and how different organisations use them, please visit www.allaboutcookies.org