void setup() {
  size (500, 500);
}

void draw() {
  background(255);
  for (int i= 0;i< 10;i++) {
    translate(30, 0);              // translating by 30 pixels to the right every time around. This is relative, so it increments
    rect (0, 0, 20, 20);          // note that the rects are drawn incrementely to the right even though the params say (0,0...
  }
}