Twilio Verify is a service that allows developers to add phone verification to their applications, reducing fake accounts and enhancing two-factor authentication. To work with Twilio Verify, developers need to create a new service in their Twilio account, assign a Service SID, and obtain their account SID and Auth Token. With these credentials, they can send verification SMSs or voice calls to users, requiring them to enter a code to complete the process. The API is simple and easy to use, with Python developers able to run verification tests directly from a shell. By implementing Twilio Verify, developers can increase the security of their applications and provide an additional layer of protection for user accounts.