Okay kiddo, imagine you have a special stamp with your name on it that you use to mark things that belong to you. Now imagine that a long, long time ago, people in ancient Israel had something similar called an "lmlk seal".
This seal had a special symbol on it that looked like four little wings spread out. They would use this seal to mark jars that held important things like food or wine. By putting their seal on it, they were letting everyone know that this jar belonged to them and that no one else should take it.
These lmlk seals have been found by archaeologists and are really important because they help us understand what life was like so long ago. They also show us how people kept track of their belongings and made sure they didn't lose them.
So just think of an lmlk seal as a really cool stamp that someone used a long time ago to say "this is mine!"