This tutorial covers how to build a flexible chat input React component that integrates with Daily's video call feature, allowing users to send messages to specific audiences, including the entire group or individual participants. The component uses Daily's `sendAppMessage` instance method to send messages and handle recipient selection, which can be either * for broadcast messages or participant session IDs for direct messages. The chat input is structured with a form that includes a textarea for message entry, a select element for choosing the audience, and an input for submitting the message. The component handles form submission, prevents page reloads, and updates the state with the received message. The tutorial also touches on potential upgrades to expand the component's functionality, such as sending messages to multiple hosts or displaying local error messages.