when to write await in nodejs code example

Example 1: await in node js

// server.js

function square(x) {
  return new Promise(resolve => {
    setTimeout(() => {
      resolve(Math.pow(x, 2));
    }, 2000);
  });
}

async function layer(x)
{
  const value = await square(x);
  console.log(value);
}

layer(10);

Example 2: await in node js

// Normal Function
function add(a,b){
  return a + b;
}
// Async Function
async function add(a,b){
  return a + b;
}