Fusion 360 is a cloud-based CAD/CAM tool for collaborative product development. Fusion 360 combines very fast and easy organic modeling with precise solid modeling.
Solid modeling is defining an object with geometric mass. Solid modeling programs usually create models by creating a base solid and adding or subtracting from it with subsequent features. Features such as extrudes, extrude cuts, revolves, radii, chamfers, etc. Examples of solids modeling programs are Solidworks, CATIA, and Fusion 3. It was originally developed for machine design, and is used heavily for engineering with large part assemblies, digital testing and rapid prototyping.
Fusion 360 is ideal to use when you are working and reworking parts for a product or design. Everything created in Fusion is, by nature, a solid and able to be 3D printed. It allows you to make changes to certain aspects of the model without rebuilding the entire model, so it is very useful in prototyping.
Fusion 360 requires a clear idea of the design to model properly and thus is not ideal for early stages of design or for complicated patterning. In these cases a surface modeler such as Rhino is more useful.