A cookie is a small piece of data that a website asks your browser to store on your computer or mobile device. The cookie allows the website to "remember" your actions or preferences over time.

They are widely used to make the web experience more personal, which is generally seen as a positive thing. Cookies collect data across website, creating 'behavioural profiles' of people. These profiles can then be used to decide what content or adverts to show you. 

Therefore, websites mainly use cookies to:

• identify users
• remember users' custom preferences
• help users complete tasks without having to re‑enter information when browsing from one page to another or when visiting the site later.
• online behavioural target advertising and to show adverts relevant to something that the user searched for in the past.

Cookies should only be used for the purposes listed above and not for user identification.

Most browsers support cookies, but users can set their browsers to decline them and can delete them whenever they like, but in that case it must be aware that without the cookies there will be certain limitations when using the site