Games consoles have built-in parental controls, which are usually accessible through the console’s home screen. These allow you to restrict users to viewing only age-appropriate games, based on the official PEGI ratings.
You can also disable in-app purchases for some games.
You can find detailed instructions about setting up controls for the following consoles on the website of the Video Standards Council: Xbox One, Xbox 360, PS4, PS3, PS Vita, PSP, Nintendo 3DS and Nintendo WiiU.
Visit gamesrating authority.org/GRA and click on ‘Controls’ in the top navigation bar.