A cookie is limited to a small amount of data and can only be read by the website that created it.
To avoid the size limitations of cookies, some websites will store a unique identification code in a cookie, and the remainder of the data in their own databases.
Cookies are generally used to:
- Store and maintain user preferences on a website
- Track user behaviour (analytics)
- Store items in shopping baskets
- Help advertisers show relevant website adverts
Cookies are not programs. They cannot perform any operations, they are not viruses or malware.
Cookies can be disabled in your browser settings, however this could make some websites unusable (e.g. e-commerce).