Why we used return 0 in c we can't use return 1 or return 2 or return 3

Question

C language

Answer 1

Main function can returns 0, 1, 2 or any number. The return 0 is here to say : 'Hey, I returned 0, all went good! Your program didn't crash!'.

Answer 2

I coded return 1 my code is complied and it's showing answer