A tesseract, also called 8-cell or octachoron, is the ?four-dimensional analog of a (three-dimensional) cube where motion along the fourth dimension is often a representation for bounded transformations of the cube through time?.
And if you understand that then you?re one step ahead of me - all I know is that this does my head in : )
source: http://conflusions.com/2007/11/20/wow-just-wow/