Twilio is a cloud communications platform that provides APIs and tools for businesses to integrate messaging, voice, video, email, authentication, and customer data workflows into their software. The platform enables developers and companies to build scalable, real-time communication experiences - for example, sending SMS or WhatsApp messages, handling phone calls, video conferencing, verifying identities, or managing customer notifications. Twilio emphasizes flexibility, extensibility, and helping businesses personalize customer engagement using data and AI, while supporting growth from startups through large enterprises.