The higher the level you are the more permissions you get granted, currently there are 4 levels.
Trust Level 0, 1, 2 and 3 (and 4 but only granted by admins so it doesn’t exists, maybe think of it like the MVP tag).
The first level 0 is basically any newcomer logs into the forums, they have so much limitations until they reach level 1.
Trust Level 1 and 2 has almost no difference aside of you give more likes.
Trust Level 3 you will no longer be blocked from posting again “until someone else post”, likes are doubled, can post links, can post images and reported level 0 users instantly hide all their posts.
To figure out which Level currently you are I made a guide for it so I don’t have to repeat everything over and over again.
Requirements for each level are changable by admins but it seems the requirements on this discourse has no difference for the default requirements which can be found here.