A SpreadSheet is a screen-oriented interactive application built around a grid in Cartesian 2 space or 3 space. Each cell in the grid contains can be empty, contain a value or contain a formula to calculate a value, usually using references to the surrounding cells. They were developed for finance but are also often used for statistics.
Generally data is sorted in a table, with the cells marked A-B-C across the top, and 1-2-3 down the side.