<application, tool> (Or rarely "worksheet") A type of
application program which manipulates numerical and string data
in rows and columns of cells. The value in a cell can be
calculated from a formula which can involve other cells. A value
is recalculated automatically whenever a value on which it
depends changes. Different cells may be displayed with different
formats. Some spreadsheet support three-dimensional matrices and
cyclic references which lead to iterative calculation. An
essential feature of a spreadsheet is the copy function (often
using drag-and-drop). A rectangular area may be copied to
another which is a multiple of its size. References between
cells may be either absolute or relative in either their
horizontal or vertical index. All copies of an absolute
reference will refer to the same row, column or cell whereas a
relative reference refers to a cell with a given offset from the
current cell. Many spreadsheets have a "What-if" feature. The
user gives desired end conditions and assigns several