Why should we start code with int main() ? What it does ?

Answer 1

int main() is the standard. void main was used in older times. It was removed as part of putting some standards

Answer 2

As of the latest standard, main() must always return int. Void/bool/char/whatever-dank-not-int-shat is not allowed.

Answer 3

It defines the main function for your program, the one that will execute first if your program has multiple functions

Answer 4

Compiler will execute anything in this method
I think you can change it to any another type
For example :
void main () or bool main()