The difference between static and non-static

Untitled

class Untitled {
  public static void main(String[] args) {    
    // Static method
    add2(1, 4);    
    
    // Non-static method
    Untitled object = new Untitled();
    object.add1(1, 4);
  }
  public double add1(int x, int y)
  {
    System.out.println("add1");
    return 0.0;
  }
  public static double add2(int x, int y)
  {
    System.out.println("add2");
    return 0.0;
  }
}