Alpha compositing

Alpha compositing is like mixing different colors of paint together to make a new color. But instead of just mixing colors, you also have something called an "alpha channel" that says how much of each color should be used.

Think of it like you have a big jar of red paint and a smaller jar of blue paint. If you mix them together without any alpha, you'll get a big jar of purple paint. But with alpha compositing, you can mix them together so that you get a lighter purple because you used more red than blue, or a darker purple because you used more blue than red.

This can be really useful when you have different images or layers that you want to put on top of each other. If one layer has an alpha channel that says it should be mostly transparent, you can put it on top of another layer and the bottom layer will show through in the transparent parts.

So alpha compositing helps you mix different colors and layers together so that you get exactly the color and look that you want.