Galaxy Structure
Galaxy structure is the shape and pattern that billions of stars form when gravity pulls them together.
Think of it this way
A big round bowl holds a swirl of sugar and spice. The stuff in the middle clumps into a dense, tight pile. The grains spread out in flat, curving bands from the center. Stir the bowl and the bands sweep into a wide, thin spiral shape.
Explaining galaxy structure by grade level
Stars do not float alone in space. Gravity pulls them close to each other. They group into big shapes, like the swirls you see in a jar of glitter paint. Our sun lives in one of these star groups.