Involve data being entered, stored, and presented in a grid on a computer. The grid is made up of a number of cells. Each blank cell is able to carry information which falls into one of three categories: Numerical data – numbers entered by user; Text – spreadsheet headings; Formulae – instructions given by user which tell the computer to manipulate the numerical data. Spreadsheets enable calculations to be made and figures to be manipulated quickly and easily and, in the case of marketing, to produce sales forecasts.