A non-modal application is one in which you can perform other tasks before you finish the task you're currently working on.
For example, a non-modal data entry form is one that the user can bring up and work with, click the mouse to switch to a second data entry form, work with the second form, and then click the mouse to go back to the first. The user can move among forms without confirming or exiting them.
A modal application is one in which you must finish what you're doing before you can do something else. For example, a user must confirm or exit a modal data entry form before he or she can work with another.
Two Ways of Creating a Non-modal Application
