This tutorial demonstrates how to remove background from a video stream using the chroma keying technique via the Agora SDK in an Agora-based video calling application. The author provides step-by-step instructions on setting up the project, initializing the Agora client, and implementing background removal. They also discuss basic terms related to media streams and tracks, as well as testing the implementation. The tutorial concludes with a note on potential optimizations and additional resources for further exploration.