Binaural audio recordings are usually made with a Binaural microphone that records sound in a similar configuration to how human ears work. Or they're just synt

Binaural audio recordings are usually made with a Binaural microphone that records sound in a similar configuration to how human ears work. Or they're just synthesized directly as a stereo signal (that's usually how those "binaural beats" music is made). They're nothing more than a stereo file, and the audio has just been recorded in a certain way that mimics the human ear and head. This is why the virtual surround sound from binaural recordings sounds so convincing, but only when wearing headphones. Spatial audio is a more generalized term. Let's say you're filming an action movie and have a scene where a robot comes from foreground-right, kicks a car, and the car flies over the camera and makes a loud crashing sound behind the camera. You can't just stick a binaural microphone on set and record that because it's almost all CGI. There is no actual sound of a robot kicking a car to be recorded. Instead your foley artists and sound design team will record and modify dozens (even hundreds) of sound sources and combine them together in software that supports a sort of virtual 3d environment, and save it in a format capable of representing this (like Dolby Atmos). You can then take that Dolby Atmos data and in realtime compute how to map your virtual sound-sources onto things like a 64-speaker Dolby Atmos array in an movie theater, or a 12-speaker home theater Dolby Atmos setup, or apply an HRTF to convincingly map that audio to 2 headphones. A Binaural audio signal is restricted to stereo and intended to be placed directly in the ears.