The Book of Inkscape, 2nd Edition

11Shapes

The freedom to do anything to anything, any time, is what makes vector graphics so attractive. With a small vocabulary of generic object types and tools for manipulating them, you can render, or at least approximate, any kind of graphic imaginable.

Absolute freedom is not always a good thing, however. For example, a path (Chapter 12) can represent any possible two-dimensional shape. Yet often, what you need is not "any shape" but a simple, well-defined geometric entity, such as a rectangle. Of course, a four-node path will give you a perfect rectangle—but isn't there a faster and more convenient way to create, specifically, rectangles?

Indeed, Inkscape has several object types for commonly used geometric shapes: rectangles, 3D boxes, ...