A polygon mesh is like a toy made out of lots of small shapes stuck together. Imagine you have a bunch of little squares and you can glue them together to make a bigger shape, like a rectangle or a triangle. That's kind of like what a polygon mesh is, except instead of squares we use different shapes called polygons.
A polygon is just a fancy word for a shape with straight sides. You might have heard of some polygons before, like a triangle (3 sides), a square (4 sides), or a pentagon (5 sides). There are lots of different types of polygons and they can have different numbers of sides.
When we put lots of polygons together to make a shape, we call it a polygon mesh. It's like putting puzzle pieces together to make a big picture. Sometimes we use polygon meshes to create 3D objects in movies or video games.
Each polygon in the mesh connects to other polygons. The connections make the edges of the polygons and where two polygons meet is called a vertex. Think of a corner of your room, that's a vertex! All the vertices and edges together make up the whole shape of the mesh.
Polygon meshes can be made of different materials like metal, plastic, or even virtual ones in a computer. They can also have different numbers of polygons which can change how detailed the object looks. So if you're playing a video game and you see a really cool 3D castle, it's likely made up of lots of polygons that form a polygon mesh!