FreeCAD is an open source program
FreeCAD was released back in 2002, and although still in beta testing, its development has progressed considerably.
Year: 2021
3D Slash is a simple free program
Perfect for beginners. 3D Slash is not like a regular program, more like a friendly, interactive 3D world where you can create whatever you want.
Tinkercad review
Tinkercad is a web service for creating 3D-objects, which is used to create simple prototypes of decorative elements, jewelry, toys and various items for further printing.
How does 3D modeling work?
The developer uses special software to process points in virtual space (called vertices) to form a mesh: a collection of vertices that form an object.