Let me outline the differences here:
Scenarios | Virtual Reality | Augmented Reality | Mixed Reality |
Augments the real world by adding objects to it. |
| X | X |
Invisibly blends virtual objects with real-world objects. |
|
| X |
Makes the user believe the experience. | X |
| X |
Replaces the real physical world with sound and vision. | X |
|
|
As you can see, virtual reality replaces the real world with a digital one but does so in such a way the user actually believes, on a more subconscious level, that what she experiences is the real thing. By this, I mean that, although the user is aware it is all fake, on a lower level she will accept the virtual world as the real world. You can see this by observing someone who rides a virtual rollercoaster in a VR environment: if she does not sit down she will probably fall down because she will compensate for the fake movements of the car. On another level, we see a similar behavior: people who see scary things in a VR world will actually be frightened, more so...