What makes Revit architecture and Autocad architecture similar but different from regular autocad? Anyone?

Both (Revit Arch & AutoCAD Arch.) are basically a BIM (Building Information Modelling) software.
We call a term called Parametric Associative which means that in both the above software, when we change anything on any of the views, all the views (Plan,Elevation, Section and3D) will be automatically changed.
This minimizes human error whereas this option is not available in the regular AutoCAD where we change any view, we have to manually change in other views which take more time, cost, resources and ultimately human error.

more better in the 3d dimensional and you got all the Architectural components.
while, the normal AutoCAD has almost all component so you will be lost somewhere if you have no background.