A demo is a trial version of a software program that you can use for a specified period of time before you decide whether or not to buy it. A demo provides the opportunity to check a program out and see whether it offers what you need, as well as whether youre comfortable with its user interface, before you spend any money.
Many software developers offer downloadable demo versions of their software on their web sites. A demo may be a fully-functioning version that works for a specified period of time, usually 15 to 30 days, and then stops working. A demo may also work indefinitely, but have some features disabled, such as the ability to save or print a file.

