Penteract - a five dimensional cube
Let's denote points by two numbers (x,y) to describe points in two dimensions. The points where both of these numbers (called coordinates) are, for example, between 0 and 1 describe a two dimensional "cube" - a square. Its corners are (0,0), (0,1), (1,1), and (1,0).
All points in three dimensions with all three coordinates between 0 and 1 describe a cube.
In 4D it's called a tesseract.
And in 5D - a penteract.