void main() function,it will flow of the program 
execution,what are the next step of line to execute.
for example,
void main()
{
int b=0
cout<<b;
int c=0;
cout<<c;
}
/*it will indicate first create object of int type,after it 
will genereate next statement.*/

void main()
//this function indicate the starting of the program furthur
tells that it has non return value.

main is the special function,,,,,,,, wch contain the 
defination of u r program or we can say it contain the main 
body of u r program.It is called as special funtion becoz 
it is invoked by the compiler itself,no any other function 
call the main().
the void is a return type which is use when no meaning ful 
value is to be return

it has no meaning it does not return any value to the 
operating system

It marks the beginning of the main body of the program and
also ensures that it is properly executed. Basically, void
main() creates the base for the program.

it shows the beginning of the program n this function is
called by the complier.here void means main()wont return any
value.