A spreadsheet is a tool for storing, manipulating, and communicating numbers. Just as a word processor can help you prepare documents that are primarily prose, a spreadsheet can help you prepare documents that are composed mostly of numbers.

Spreadsheets can be used to bring order to your financial calculations. For example, if you are thinking of purchasing a new car you may want to create a worksheet that will estimate the costs.

Without a spreadsheet, your notes might look like:

With a spreadsheet you can neatly record numeric information:

A spreadsheet also provides built-in support for complex calculations such as the monthly payment on a loan given the loan amount, interest rate, and number of years financed. Perhaps the greatest value a spreadsheet provides is the capability to perform "what-if" calculations. For example, if you create a spreadsheet to calculate the cost of a new car you can easily change one of the entries such as purchase price or interest rate, and see immediately what impact the changes will have on the other dependent numbers. This allows you to answer questions like, "what if I bought the more expensive car I really want...???"

The first spreadsheet application, VisiCalc, was written in 1979 by Dan Bricklin (Harvard) and Bob Frankston (MIT). It was one of the first widely used applications and helped start the Personal Computer revolution. Today the most popular spreadsheet applications are Lotus 1-2-3 and Microsoft Excel.