Cookies are small sections of text that act as information markers, they are sent by a server (in this case, the Site/APP server) to a user's device (usually the Internet browser) when the user accesses a given page of a website. Cookies, which can also be created by websites other than the sites the user is currently viewing ("third party cookies"), are automatically stored by the user's browser and forwarded back to the server that generated them each time the user accesses that same page on the Internet. Cookies thus allow and/or facilitate access to certain Internet pages, for example to improve user navigation (i.e. they make it possible to store the pages you have visited and other specific information, such as your more frequently viewed pages, connection errors, etc.), or enable sites to build profiles about users. To use websites easily and completely, therefore, users are advised to configure their browsers to accept these cookies.
Often, browsers are set to accept cookies automatically. However, you can change the default configuration to disable or delete cookies (from time to time, or once and for all). You should be aware, however, that doing so may prevent you from being able to use some areas of the website in the most effective way. You can also check how and what types of cookies are stored on your browser by changing your browser's cookie settings.