A long time ago (1993) , in a place far, far away (San Diego, California) there lived a small company called FutureWave Software. They produced a software program named SmartSketch a vector-based drawing program and at one time the number one drawing program on the Macintosh in Japan.
SmartSketch had all kinds of "friendly" features, very different from the dominant drawing program of the day, Adobe Illustrator.
In 1995 they decided to add animation to vector drawing and released FutureSplash Animator, a program for creating animations on the web. Soon after, Macromedia acquired FutureWave and in a victory for the Society of Short Syllabic Words changed the name to Flash.
Macromedia however didn't release SmartSketch under the Macromedia banner, they had already acquired Freehand, another vector-based drawing program which competed with Illustrator and saw no need to muddy the market further... but don't despair, SmartSketch still lives!
Even though Macromedia, and now Adobe, have tweaked it, the guts of the drawing program in Flash today is still essentially SmartSketch. If you've used the drawing program in Flash you know what I mean: the" intelligence" behind the pencil tool options: "straighten", "smooth" and "ink"; the "knocking out" and joining together of graphics, the "natural drawing" tools, that's all from SmartSketch now playing nicely and in the same family as the program it once tried to rebel against, Illustrator.
People coming to Flash with no Illustrator experience enjoy working with it once they get the hang of it; Illustrator users may complain a bit, but additions to the Flash drawing program, the Pen tool, for instance, make Illustrator user's feel a bit more at home, still it's different enough to be a bit of a pain for hard core Illustrator power users and certainly it's not as powerful.
Illustrator user may want to skip it: these days with better integration between Flash CS3 and Illustrator CS3, there's less need to use the drawing program in Flash, just create in Illustrator and import into Flash.
More on that some other time.
If you're not an Illustrator aficionado yet you may just want to stick with SmartSketch, otherwise known as the drawing program inside of Flash.