Cookies are small packets of data that are stored by a website on a user's computer. They are often used to track website activity, store login information and personalise a user's experience on the website.

When a user visits a website, the website server may send a cookie to the user's computer. The user's browser then stores the cookie and sends it back to the server each time the user visits the website again. This allows the website to recognise the user and customise the user experience based on their previous activity on the website.

Cookies can be useful for a number of purposes, such as remembering a user's login information or preferences. However, they can also be used to track a user's activity on different websites and to serve targeted advertisements. Some users may choose to disable cookies or delete them after each browsing session to protect their privacy.