Specifically, EnergreenSpain uses:
Google Analytics: used to analyze the user’s browsing experience, and allow us to improve our website to suit your needs. They normally remain in the user’s browser for a period of time, until the cookies are deleted from the browser or the time defined for their elimination has elapsed. They are called _ga, _ga*, and _gid. More information: https://support.google.com/analytics/answer/6004245?hl=es
For more information on what cookies are, what they store, how to delete them, disable them, you can go to this link.