Single point of failure

Okay, so imagine you have a toy that needs two batteries to work. If one of the batteries runs out, the toy won't work anymore. But if you have another toy that only needs one battery, even if that battery runs out, it won't affect the other toys.

Now think about a big computer system that has lots of parts that need to work together to make it run. If there's one part that's really important and it stops working, the whole computer system might stop working too. That part is called a single point of failure because if it fails, the whole system fails too.

It's like if you were building a tower with blocks, and one block at the bottom was really important to keep the tower up. If that one block fell, the whole tower would fall too. That block is the single point of failure.

So, it's very important to make sure that computer systems, toys, and anything else that has parts that need to work together, don't have single points of failure. We want to make sure that if something stops working, it won't affect the whole system.