why in Keil compiler we define the main as int rather that void ?
int main (void)
rather than ....
void main (void) ,like in C51
"But when devoloping code for 8051 we dont use int main. why?"
Because C51 isn't strict ANSI/ISO.
"what is the deifference?"
It should be obvious by now; one is strict ANSI/ISO and the other is not.