I have been reading a few books lately and browsing the internet for an explanation on the concept of "four-dimensional" space (or, space-time, as some of them have been calling it). But, what those books and sources did majorly was confuse me.
In some places, I see the author calling it "four dimensional space-time", where the fourth dimension is Time, and at other places, another person says, "Time is not any dimension at all. The fourth dimension is a dimension perpendicular to the cube". About the tesseract/Hypercube etc. I tried reading about the Hypercube and I was almost convinced that Time is not really a dimension when a few other books I read (on Einstein's General Relativity) started calling it the "curved 4-Dimensional space-time", to further confuse me.
Would be glad if anybody could explain these concepts and the difference, if any, between them. Or could anyone recommend any books or articles on them? Thanks in advance.