Gadgets are some kind of predefined tokens that will embed 3rd party controls on the page providing specific functionalities. The difference is these come from the configuration files and they are very specific about what they integrate with. Except ease of use, there is no real benefit to using or creating gadgets compared to creating custom tokens or razor scripts.

The gadgets are stored in configuration files on disk at ~/DesktopModules/avt.MyTokens/Gadgets.