Twilio is a communication platform that allows developers to make phone calls and send text messages using its API. To demonstrate this, the article uses PHP and the Twilio REST client to create a phone call and send a text message. The process involves authenticating with Twilio's account credentials, creating instructions using TwiML (a subset of XML), and sending these instructions to Twilio's API. The article provides example code for both making a call and sending a text, showcasing how to customize the content of the calls and texts using different URLs. With this setup, developers can now communicate more effectively with notifications, updates, reminders, and other programmable communications.