Note: Woots have been replaced by Likes and Favorites.
Woots are stars with red bows that can be given from players to worlds as a way of rating a World good. In the lobby, worlds can be sorted by the amount of Woots. Originally, "Woot" was another term for magic coins after they were re-added, but as of November 21, Woots and magic coins were separated to prevent further confusion.
As of August 20, 2015, Woots have been replaced by likes and favorites.
According to the update 2.0 blog, Woots were completely meaningless. Players can spend a large amount of Woots on a level, either by coming back each day, rejoining or using extra accounts. The blog also said that players woot to get edit rights, Woot to get "golds" in a bot level, Woot to announce them leaving the level, or Woot because they have 10 of them and they don’t know what to do with them.
Woots were supposedly meant to be a display of quality, to praise a world. However when it was first implemented it missed the mark due to its design as the result of Woots being replaced.
If a player wants to, they can give a world a Woot. People often put fun and entertaining things in their worlds to encourage people giving Woots. The special Woots used for giving to worlds have a red bow on them. Every day, the player will receive 10 more Woots to give to worlds.
If Woots are attempted to be saved for the next day, the amount of Woots a player has is capped at 10, making the unused Woots yesterday go to waste. The worlds can now be (and already are, by default) sorted by how many Woots they have, although do be aware that worlds with lots of Woots can often be found with little to no people in it. As Woots burn away, a popular world may not have the same popularity the next day, giving other worlds a chance to have more Woots.
Woots were capped to five for each user before February 24, 2015.