Why do we need to compile for different platforms (e.g. Windows/Linux)?

Question

I\'ve learned the basics about CPUs/ASM/C and don\'t understand why we need to compile C code differently for different OS targets. What the compiler does is create Assemble

Answer 1

In addition to everything else even with identical instructions even the calling conventions can differ, that is the placement of parameters on the stack or in registers, the order parameters are found, what registers must be preserved across a function call, how return values are passed from callee to caller.