If you haven't purchased a copy of Moho, then the program will be running in "demo" mode. While in demo mode, Moho still allows you access to all features of the program. Anything you can do in the full version you can do in the demo. Also, any files you create with the demo version of Moho will still work fine if you purchase the full version.
The demo version has just two limitations: First, when you render your animation for final output, a "DEMO" watermark will appear on top of your animation. Second, if you export to the SWF (Flash) format, your animation will appear in black & white. If you purchase a copy of Moho, the demo watermark will go away, and you will be able to export SWF files in full color. To purchase Moho, click here.