The main concept behind the FreeCAD interface is that it is separated into workbenches. A workbench is a collection of tools suited for a specific task, such as working with meshes, or drawing 2D objects, or constrained sketches. You can switch the current workbench with the workbench selector. You can customize the tools included in each workbench, add tools from other workbenches or even self-created tools, that we call macros. Widely used starting points are the PartDesign Workbench and Part Workbench.