A cookie, is a small information sent by a website and stored in the user's browser, so that the website can consult the previous activity of the user.

Its main functions are:

         · Take control of users: When a user enters their username and password, a cookie is stored so that they do not have to be entered for each page of the server. However, a cookie does not only identify a person, but a combination of computer-browser-user.
        · Get information about the user's browsing habits, spyware attempts (spyware), advertising agencies and others. This can cause privacy issues and is one of the reasons why cookies have their detractors.
Cookies can be deleted, accepted or blocked as desired, for this you should only conveniently configure the web browser.

Cookies are usually used by web servers to differentiate users and to act differently depending on them.

A use of cookies is to identify yourself on a website. Users are usually identified by entering their credentials on a validation page; Cookies allow the server to know that the user is already validated, and therefore can be allowed to access services or perform operations that are restricted to unidentified users.

Other websites use cookies to customize their appearance according to the user's preferences. Sites that require identification often offer this feature, although it is also present in others that do not require it. Personalization includes both presentation and functionality.

Cookies are also used to track users along a website. Tracking on a single site is usually done with the intention of maintaining usage statistics, while cross-site tracking typically targets the creation of anonymous user profiles by advertising companies, which will then be used to target campaigns (Decide what type of advertising to use) based on user profiles.