This tutorial provides a comprehensive guide on how to create an in-browser voice chat application using Nexmo's API and Vue.js, with Express.js as the server-side framework. The application allows users to join or create conversations, authenticate themselves with a JWT token, and manage audio playback. The tutorial covers setting up the project, creating the server-side API endpoints, implementing the client-side UI components, and connecting the two. It also discusses how to add features such as user management, message sending, and call handling. The application is designed to be scalable and maintainable, with a focus on separation of concerns between the client and server sides.