A percussion ensemble is like a big team of musicians that use different types of drums, metal instruments, and other stuff that makes noise to make music together. It's kind of like playing a game where everyone has their own special equipment and job to do, but they have to work together to win.
Imagine going to a playground with your friends and each of you has your own toy to play with. One friend has a bucket and a stick to make drum sounds, another friend has a metal triangle to make ringing sounds, and another friend has a xylophone to make high-pitched notes. When you all play together, it makes a really cool sound that is much better than when you play alone.
That's what a percussion ensemble does, but on a bigger scale with lots of different types of instruments. They practice playing different rhythms and patterns together and come up with cool songs. They can make music that sounds like a marching band, or a Latin dance party, or even like an orchestra with different sections of instruments.
Percussion ensembles are really fun to watch because the musicians move a lot and all the different instruments make really interesting sounds. Plus, it's neat to see how a big group of people can work together to make something so cool!