Okay, kiddo, so let's imagine we are playing a game together. In this game, we both have to clap our hands at the same time, like this ^clap^.
Now, it's very important that we clap our hands at the same time because if we don't, we might miss the goal or get in trouble. So we need to make sure we always clap together.
This is what isochronous timing means - doing something at the same time in a really precise way. It's like when a group of people dance together and they all move their arms and legs at the same time. That's isochronous timing too.
It's a bit like a clock as well. When the clock ticks, it goes tick-tock-tick-tock, and each tick and tock happens exactly the same amount of time after the last one. That's what makes the clock tell time in a really precise way.
In the same way, isochronous timing makes sure that things happen at the right time and in the right order. It's really important for things like music, where if the timing isn't right, it won't sound very good. So we use isochronous timing to make sure that everything happens exactly when it's supposed to.