while(x) means in c code example

Example 1: WHILE loop in c

while( a < 20 ) {
      printf("value of a: %d\n", a);
      a++;
   }

Example 2: do while loop in c

//This program stops when a number greater than 10 is printed and prints that, value greater than 10
#include <stdio.h>
main()
{

    int a;
    do
    {
        printf("\nEnter your value: ");
        scanf("%d", &a);
    } while (a<10);
    printf("Value greater than 10");
    
    
}