After executing setup() function, which initializes and sets the initial values, the loop() function does precisely what its name suggests, and loops consecutively, allowing your program to change and respond. Use it to actively control the Z-Uno board.
void setup() {
  // put your setup code here, to run once:
  pinMode(5, OUTPUT);

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(5, HIGH);