Layer
A system that separates an image into multiple transparent sheets stacked on top of each other, allowing independent editing of each level.
A layer is a transparent sheet within an image editing system. Multiple layers stack on top of each other, and each can be edited, moved, or toggled independently without affecting others. Layers are a core feature of editors like Photoshop and GIMP.
For example, a background photo layer can have a text layer placed above it, with a logo layer on top. Editing the text only modifies that specific layer without touching the background. Reordering layers changes the front-to-back arrangement freely.
Each layer supports opacity settings, allowing semi-transparent effects where lower layers show through. Changing the blend mode alters how layers combine, with options like Multiply, Screen, and Overlay. Combined with masks, layers enable advanced editing where only portions of a layer are visible.