While Model Space is typically used while creating geometry, Paper Space is geared toward creating the final layout of your drawing for printing or plotting on paper. In Paper Space, you typically arrange drawing elements on one or more sheets of paper.
The Paper, the large white rectangle in the middle of the drawing window, shows you how your drawing will be laid out on the page when printed. You do not have to draw on the paper; you can draw anywhere in the drawing space and later fit the drawing to a sheet of paper. You can also turn off the paper sheet shown. The pattern of horizontal and vertical lines, which may be shown on the paper, is the grid that marks exact locations in the drawing.
Tip: You can use the TC Explorer Palette to see all Paper Spaces defined for any open drawing. See Drawing Settings.