Virtual reality is a simulated environment designed within a computer. You enter a virtual reality, where you can act out motions as normal in the ‘real world,’ as these will be replicated by a digitized version of yourself in the artificial reality.
A virtual reality environment could be identical to the real world or not. It all depends upon the wishes of the users. All surroundings will be rendered in three dimensions, however, and all items encountered in virtual reality must be of a proportionate size to their real-life counterparts.