download-data.js

async function processData() {
  const data = await downloadData();
}

multiple-services-serial.js

async function processData() {
  const data1 = await downloadFromService1();
  const data2 = await downloadFromService2();
  const data3 = await downloadFromService3();
  
  ...
}

multiple-services.js

async function processData() {
  const promise1 = downloadFromService1();
  const promise2 = downloadFromService2();
  const promise3 = downloadFromService3();
  
  const allResults = Promise.all([promise1, promise2, promise3])
  ...
}