Level Links are items introduced in LittleBigPlanet 2 that are used to, as the name entails, link levels. They either look like regular level badges or doors, depending on which game you're playing, and when all players are together you can activate it to go into a different level. The only real difference from linked levels to unlinked levels is that you will keep your score for the previous level. Before you enter a Badge-shaped Level Link, the character you're playing as will wave goodbye (or peck the ground in Swoop's case, or move their head a bit in OddSock's case) then jump in. When used in community levels, players can review the level they are in and then move on to the next level. While in the next level player can choose to go back to previous level.
In Create Mode, the Level Link cannot link to other levels on My Moon, (only levels that are already published can be linked) so unless the Level Link is in an Adventure with other levels, it requires an internet connection to be used.
In LittleBigPlanet 3, Level Links take on the form of doors instead of Badges like in LittleBigPlanet 2 and LittleBigPlanet PS Vita, but apart from a shortened animation, it functions largely the same as it did in the previous game.