A spreadsheet is a computer program organizing cells, containing numbers, dates, or text, into columns and rows. Then the values of these cells are used in formulas in other cells to give results. When a number is changed in one place, the results of other cells change immediately. This is extremely useful for business forecasting, bookkeeping, and so forth.
Microsoft Excel is currently the leading, or most popular, personal computer spreadsheet. It is available as part of the Microsoft Office application suite, for Windows or Macintosh.
Developers and consultants providing more general or diversified services should be listed in a more appropriate category.