You can then edit each layer without affecting the ones beneath it. Also: How to use Layers in the GIMP image editor If you were to try and edit a complicated image without using layers ...

G'MIC Qt is a powerful collection of effects that makes it possible to manipulate your images (or layers) in such a way that combines multiple filters for a single effect. For example, you can add ...

instead of a confusing floating layer. This alone makes GIMP a lot easier to use, in my opinion. The paintbrush tool can now automatically expand the size of the selected layer if you paint over ...