int pinInput = 2;
int pinOutput = 13; // LED_BUILTIN
int switchState = 0;

void setup() {
  // put your setup code here, to run once:
  pinMode(pinInput, INPUT);
  pinMode(pinOutput, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  switchState = digitalRead(pinInput); // will read HIGH OR LOW
  digitalWrite(pinOutput, switchState);


  /* So if we pushed the button, the pinInput (2) will be connected to 
    HIGH (+)
    else the pinInput will be connected to the PULLDOWN resistor which is connected
    to LOW (-)
  */
}