Cookies are small files with information a website stores to a user computer, so when the user connects to the website, the website retrieves the information and offers the associated services.
Technical cookies are required for connecting to the website or providing the services that the user requested. So the Cookies that are exempt, are the ones that are technically requiered for connecting to the website or providing the internet services.
Non essential Cookies for the operation of the website (they are installed by your consent, which you can revoke at any time). These Cookies are used in order enhance the experience of the website user, by retriving the statistic information. They are stored anonymously and a random number is assigned for the recognition of the unique website user.