Cookies are small pieces of information sent by a web server to the client (browser) to store some information locally, related to that specific user. In modern web applications, cookies are used to store user-specific data, such as color theme configuration, object arrangement preferences, previous activity, and (more importantly for us) the session identifiers.

In this recipe, we will use the browser's tools to see the cookies' values, how they are stored, and how to modify them.