Well for us scratch builders that start with a 3"x3"x36" block of balsa and don't have a manual, "YES", there is a huge difference between assemble and build. Next time you need some epoxy, after squeezing both part's into the container, try shaking instead of stirred. Both will mix it but one will be better than the other!!!!
My definition of build is to manufacture the parts that build the airframe. After the airframe is "built" I assemble the hardware and install the engine.