The speaker discussed the implementation of the WebHID API, an experimental browser API that enables communication between devices and applications on the web. The API allows users to create applications that can interact with bidirectional communication devices, receiving input from and delivering output to the user. The talk included a demo of how a PS5 controller can be used to control an application and included code snippets to help developers understand how the WebHID API can be implemented. The speaker also shared other web applications that use the WebHID API to give attendees a better understanding of how it can be used.