how goto use stament

what is goto stament in c?

how use goto in programm

#include<stdio.>
#include<conio.h> // who Linux user pleseRemove this

int main()
{
int i=0;

goto a;
na:       
printf("Not allowed = %d\n",i);
a:
    for(i=i+1;i<=35;i++)
    {
        if(i==15||i==30)
        goto na;
        else
        printf("Allowed =%d\n",i);
    }
        
 getch(); // who Linux user please Remove this

 return 0;
     
}