When you build interactive canvas applications with Konva.js, you use two essential building blocks: the stage and layers. The stage is the root container that holds everything you draw—it represents your main canvas and is where you attach all other visual elements. Every Konva.js app starts by creating a stage, which specifies the area where users can see and interact with shapes.

Within the stage, you organize your content using layers. A layer in Konva.js acts as a separate drawing surface stacked on top of the stage. Each layer is independent, which means you can manage, show, hide, or redraw groups of shapes without affecting others. This is especially useful for optimizing performance and for structuring your app—for example, you might want to keep background elements on one layer, interactive shapes on another, and UI overlays on a third.

Layers allow you to group related shapes together. For instance, you might keep all drawing tools on one layer and annotations on another. This structure gives you fine control over rendering and user interaction, making your canvas app more efficient and easier to maintain.