That is an anime streaming site. Its a site about anime cartoons, and it usually has them dubbed in multiple languages: English, Portuguese, Spanish etc. They have not got everything, but everything has at one time or another been on Crunchyroll.
They stream new episodes one week after aired on TV in Japan. Paying members see them 1 hour after the shows air.
A lot of properties are no longer available there and can only be gotten in other ways, but new things are usually there as well as full sets of some popular titles. If you want to see all 200+ episodes of Dragonball Z you can, or all of One Piece, or all of Fairytale.
Some titles have been sold either partially or entirely to Amazon. For example you cannot see Girls Last Tour on Crunchyroll, but at one time you probably could have. Season 1 of "Is it Wrong to Try to Pick Up Girls in a Dungeon?" is on Amazon, but you can only get seasons 2 and 3 on Crunchyroll.