Spatial audio refers to when a game developer manipulates audio volume and mechanics in order to mimic the nature of real-world sound cues; for example, if an asset creating a sound is coming from the player's left, then the audio must bend and echo from the left in the same way it would if that asset were making a sound in real life. This also helps the player know where an important asset is, and so therefore what to look at in regards to the story - like all video games, spatial sound in VR can not only help with immersion, but can be an aid to storytelling.
Of course ambience is incredibly important when creating a 3D world, especially if (for example) you're working with a forest or a river. This is known as linear audio design, as it is constant, and not usually triggered by the player or any of the assets. If you were to have a cutscene, however, triggered by the player interacting with an NPC, that would be interactive sound design. While these sound types are not different in regards to playback and recording, the workflow to create the differing sounds is quite different.
When creating a virtual reality experience, especially when creating a VR game, music is of course a huge part of immersing the viewer in whatever world you have chosen to create. Creating a soundtrack that is relevant to the environment and worldbuilding can be extremely useful in any game. Take, for example, soundtrack for the indie game Undertale. Not only is that an extremely nostalgic and enjoyable soundtrack in general, however the digitally-created musical style fits with the indie art style and feel of the game. This immerses the player in the world of the game, and provides background audio that feels like it fits with the gameplay. As well as this, the individual tracks match with the environment in which they are played in. For example, the track "waterfall" plays when the character is exploring a watery cave system, and so contains lots of high-pitched echoing sounds (which are almost reminiscent of crystals, or water falling) to match this environment.