In This program # is a pre processor and stdio.h is standard input output library file and .h is hidden file.
conio.h in conio is console input output file and .h is hidden file.
void is default data type, it is accept value.
main() is function and program body maintain in this function.
clrscr() is clear screen function, that is clear the screen at ru ntime.
printf() is a function to print the output.
getch() is also function. it is use for hold the output screen at the run time.