A cookie is a small text file that is downloaded and stored on the user's computer when the user opens a website.
The cookie is used, for example, to store login details, remember the shopping cart in the online store, or register where the user moves around the website.
Cookies can be useful for both the owner and the user of a website. The website owner can customize the service based on the information stored. For the user, a visit to the website can be more user-friendly and customized.