Minecraft mobs drop all sorts of loot, some of which are pretty valuable. A lot of them drop food or other useful crafting, so it's a good idea to farm them.

Need XP fast in survival? This tutorial shows you how to build the easiest mob XP farm in Minecraft 1.21+ — no spawner ...

Mob spawner is an essential build in every Minecraft world, so here is how you can make a mob farm in the sandbox game.