Lingo, Director's scripting language, adds interactivity to a movie. Often Lingo accomplishes the same tasks-such as moving sprites on the Stage or playing sounds-that you can accomplish using Director's interface.
Much of Lingo's usefulness, however, is in the flexibility it brings to a movie. Instead of playing a series of frames exactly as the Score dictates, Lingo can control the movie in response to specific conditions and events.
For example, whether a sprite moves can depend on whether the user clicks a specific button; when a sound plays can depend on how much of the sound has already streamed from the Internet.
Behaviors are pre-existing sets of Lingo instructions. Attaching behaviors to sprites and frames lets you add Lingo's interactivity without writing Lingo scripts yourself.
If you prefer writing scripts to using Director's interface and behaviors, Lingo provides an alternative way to implement common Director features; for example, you can use Lingo to create animation, stream movies from the web, perform navigation, format text, and respond to user actions with the keyboard and mouse.
Writing Lingo also lets you do some things that the Score alone can't do. For example, Lingo's lists let you create and manage data arrays, and Lingo operators let you perform mathematical operations and combine strings of text. You can also write your own behaviors that perform tasks beyond those possible with the behaviors that you already have available.