The MediaStream API is a crucial tool for web developers when working with audio and video inputs. This post provides an overview of the basics of the MediaStream API, including getting started, properties, methods, and events. Key points include understanding how to gain access to user's audio/video devices using getUserMedia method, the concept of a 'stream' consisting of one or more 'tracks', various properties like active and id, methods such as addTrack, getTracks, removeTrack, and events like onaddtrack and onremovetrack. Understanding these concepts can help developers effectively utilize the MediaStream API in their applications.