Hyper-Space refers to two things, a method of travel and a dimension
Hyper-Space, the dimension is an aspect of a Space-Time Zone (A universe), a higher dimension, it is where all alternate dimensions exist. Hypers-Space is generally used to refer to all Higher Dimensions within a Universe. It is also a term used by some to refer to the space between Universes. (The Multiverse)
Means of TravelEdit
Hyper-Space, the means of travel is a four dimensional subspace field used in conjunction with warp drives for even faster travel. The amplify travel by a factor of ten.