Cookies are small text files that websites store on your device (such as your computer or mobile phone) when you visit them. 

They are used for several reasons:

•     Personalization: Cookies allow websites to remember your preferences and settings, which improves your user experience. For example, they can remember your language or page theme.
•     Authentication: They help you log in to websites by remembering your login details, so you don't have to log in repeatedly.
•     Analytics: Cookies are used to track website traffic and user behavior, which helps websites improve their content and functionality.
•     Advertising: They enable the display of targeted ads based on your interests and previous website visits.