FreeCAD is a general purpose parametric 3D CAD modeler. The development is completely Open Source (LGPL License). FreeCAD is aimed directly at mechanical engineering and product design but also fits in a wider range of uses around engineering, such as architecture or other engineering specialties. FreeCAD features tools similar to Catia, SolidWorks or Solid Edge, and therefore also falls into the category of MCAD, PLM, CAx and CAE.
- Autocad is a 2d cad mostly. Freecad is a parametric design software. Different purposes different design paradigm.
- FreeCAD is a 3D parametric CAD whereas AutoCAD is more oriented for 2D drawings. On the other hand, FreeCAD is still buggy and lacks of important workbenches (whereas others like a robot simulator are available even if they are not suitable for a professional use)
- Because is an user friendly software and is free to use.Autodesk Autocad is very expensive