Why There is a difference between assembly languages like Windows, Linux?

Question

I am relatively new to all this low level stuff,assembly language.. and want to learn more detail. Why there is a difference between Linux, Windows Assembly languages?

Answer 1

Assembly language is related to CPU architecture not with O.S., but O.S. have a series of system function compiled in binary that your assembly program can invoke, by interrupt calling. For example standard input output , operation ecc....