Layers are the basic building blocks of content in Sketch.
Unlike in other applications where the distinction between layers and objects is blurred, in Sketch, each object is always on its own layer. We’ll be using the terms object and layer interchangeably throughout this manual for that reason.
Groups and Artboards are used in Sketch to keep your content organised and they are also treated as layers in their own right. To add new layers to your document, click the Insert icon the toolbar or go to the Insert menu in the application’s global menu.