This tutorial demonstrates how to develop a web application that supports speech-to-text transcription using JavaScript's Web Speech API, Agora Web SDK, and the Agora RTM SDK. The application allows users to join video calls and transcribe their voice into text, which can be read by others in the channel. The tutorial covers setting up the HTML structure, adding CSS for styling, implementing core functionality using JavaScript, and integrating voice-to-text services with Web Speech API and RTM. The final application allows users to join video calls, transcribe their speech into text, and send the transcriptions to all other users in the channel.