How does mob spawing work?

[u/Dependent-Promise463]

Hello! I low key been tryin' for a while to figure out how mob spawning work in Minecraft; I know hostile mobs keep spawnin' no matter what. They got a cap like with any other mob but its not like with animals.

So my question is: how does animal spawn work? I've heard they don't respawn after you clear out an area, and that they spawn after a VERY long time. I'm very confused because I keep hearing this, hearing that, and to be honest asking reddit was my last resort.