text: // Asynchronously (non-blocking)
  
  const { readFile, writeFile } = require('fs');
  
  console.log('Start task');
  
  // It works asynchronously by using a callback functions.  
  readFile('./Content/first.txt', 'utf-8', (err, result) => {
    if (err) {
      console.log(err);
      return;
    }
    const first = result;
    readFile('./Content/second.txt', 'utf-8', (err, result) => {
      if (err) {
        console.log(err);
        return;
      }
      const second = result;
      writeFile('./Content/result-sync.txt',
        `Here is the result: "${first}" and "${second}"`,
        (err, result) => {
          if (err) {
            console.log(err);
            return;
          }
          console.log('Done with this task');
        });
    });
  });
  console.log('Starting next one');
  