Sometimes when you put your socks in the laundry, one of them disappears and you can't find it anymore. This is called a missing sock. It's like when you lose a toy or a piece of puzzle and you don't know where it went.
There are a few reasons why a sock might go missing. One is that it might get stuck inside the washing machine or dryer. When the machine is spinning around and around, the sock might fall into a little crack or hole where you can't see it.
Another reason is that it might get mixed up with other clothes or socks. Sometimes when you take a sock out of the dryer, you end up with more than one sock that looks similar but doesn't match. This can be confusing and make it hard to find the missing sock.
But don't worry too much about it. We can always just wear another pair of socks. And who knows, maybe someday the missing sock will show up again when we least expect it!