Twilio is a company established in 2008, initially offering Twilio Voice for programmatically making and receiving calls, and later expanding to include a wide array of communication services, such as SMS, email, fax, and chat. The company simplifies the process of integrating these services into web applications by handling interactions with carriers, allowing developers to focus on building their products. Twilio offers APIs like Lookup, Phone Number Verification, and SMS on platforms like RapidAPI, each with specific pricing structures. A practical example is demonstrated using a Rails application, where Twilio's SMS API is used to send shipping notifications to users, illustrating the integration of Twilio's services in application workflows. Twilio's offerings extend beyond SMS to include WhatsApp messaging and two-factor authentication, while also managing rate limits and message queuing to ensure compliance with carrier regulations.