Twilio Conversations is a messaging service that allows developers to add bidirectional messaging capabilities to their applications using Twilio's SDKs and APIs. In this tutorial, users will use the Twilio Conversations JS SDK to add bidirectional messaging capabilities to an agent portal built in Retool, a development platform for internal tools. The tutorial requires a Twilio account, a phone number, a Retool account, and a high-level understanding of Retool. The user will set up their Twilio account, create API keys, services, and functions, and deploy the Twilio Service to use it with the Retool app. The Retool app code is then imported into the Retool instance, and the user can explore the app to send and receive messages between the Retool app and a phone number. The tutorial provides a powerful and easy-to-use toolkit to build custom chat-enabled internal applications.