Twilio is a cloud communication platform that enables developers to build software on the internet using common protocols and simple markup, providing a bridge between the internet and telephony networks. It simplifies worldwide connectivity by interacting with Twilio's platform, which is much simpler than traditional telecommunications. Twilio provides a virtual presence on the physical telephony network through phone numbers, allows developers to turn real-world events into virtual signals that software can handle, and offers various products and services such as voice and messaging communications, public REST API, and short codes.