What are cookies?
For most websites to work properly, they need to collect certain basic information on its users. To do this, a site will create files known as cookies – which are small text and/or numerical files – on its users' computers and/or browsers.
Cookies do a lot of different jobs which make your experience of the Internet much smoother and more interactive. For instance, they are used to remember your preferences on sites you visit often, to remember your user ID and the contents of your shopping baskets, and to help you navigate between pages more efficiently. They also help ensure that the advertisements that you see online are more relevant to you and your interests.
Much, though not all, of the data that they collect is anonymous, though some of it is designed to detect browsing patterns and approximate geographical location to improve user experience.
What types of cookies are there?
Broadly speaking, there are four types of cookie: strictly necessary cookies, performance cookies, functionality cookies and targeting or advertising cookies.
- Strictly necessary cookies are essential to navigate around a website and use its features. Without them, you wouldn't be able to use basic services like shopping baskets and e-billing.
- Performance cookies collect anonymous data on how visitors use a website; they can't track users, and are only used to improve how a website works.
- Functionality cookies allow users to customise how a website looks for them: they can remember usernames, language preferences and regions, and can be used to provide more personal services like local weather reports and traffic news.
- Advertising and targeting cookies are used to deliver advertisements more relevant to you, but can also limit the number of times you see an advertisement, and be used to chart the effectiveness of an ad campaign by tracking users' clicks. They can also provide security in transactions. They are usually placed by third-party advertising networks with a website operator's permission, but can be placed by the operator themselves. They can remember that you have visited a website, and this information can be shared with other organisations, including other advertisers.
Additionally, these cookies break down into two further sub-types;
- Persistent cookies remain on a user's device for a set period of time specified in the cookie. They are activated each time that the user visits the website that created that particular cookie.
- Session cookies are temporary. They allow website operators to link the actions of a user during a browser session. A browser session starts when a user opens the browser window and finishes when they close the browser window. Once you close the browser, all session cookies are deleted.
You can find more information about the individual cookies we use and the purposes for which we use them in the table below:
You can block cookies by activating the setting on your browser that allows you to refuse the setting of all or some cookies. However, if you use your browser settings to block all cookies (including essential cookies) you may not be able to access all or parts of our site.
Effective from 17/03/2020 Last reviewed 17/03/2020 Version 1.1