In its simplest definition, a tesseract (or “hypercube”) is the 3-dimensional shadow of a cube in the fourth dimension.

You and I can only consciously perceive 3 dimensions (consisting of height, length and width) with our senses, but mathematics and physics shows us that there are many possible dimensions. Four dimensions are required to explain how gravity works. Theoretical 4-D structures can be plotted on 4 axes: