You're going to learn how to create a Node.js application powered by Twilio Functions to receive phone calls on your Twilio number. To follow this tutorial, you need a free Twilio account, a Twilio phone number, and the Twilio CLI. You'll set up a new Twilio Functions service, deploy a serverless environment, and create a protected function that receives incoming phone calls. The protected function uses TwiML to play a message when someone calls your Twilio number. After deploying your function, you'll configure the Voice webhook in the Twilio Console to direct incoming calls to your function. Finally, you'll test your Twilio phone line by calling the purchased number and hearing a pre-recorded message.