球球各位大佬能不能讲一下这个是啥，刚开始自学编程还不太会

#include <math.h>
#include <stdio.h>
int main()
{
double x,s;
printf("input number:\n");
scanf("%lf",&x);
s=sin(x);
printf("sine of %lf is %lf\n",x,s);
return 0;
}