An archaeological horizon is kind of like a big invisible line in the ground that we use to make sense of things that people may have left behind a long time ago. Just like how we use lines on a map to show where different countries are, we use horizons to show where different time periods are in the ground.
Think of it like this: imagine you have a big pile of all your toys on the floor. You might put all your stuffed animals in one pile, your action figures in another, and your Legos in a third pile. Just like that, we can use horizons to sort things that people might have left behind into different piles based on when they were made or used.
This helps us better understand what life was like a long time ago, and how people used to live. By studying different archaeological horizons, we can learn about everything from primitive tools and weapons, to ancient artwork and even buildings!