The MAXWrapper Value classes are the core 3ds Max classes that are supported directly within MAXScript. Many of the kinds of 3ds Max objects you will work with are provided through 3rd-party plug-ins for 3ds Max, they are not built directly in to MAXScript.
For these classes, an automatic plug-in detector scans for plug-ins that MAXScript doesn't internally know about and attempts to provide MAXScript access to them. This includes new core classes in new releases of 3ds Max that MAXScript doesn't internally know about, and 3rd-party plug-ins. Not all parameters and properties of the detected plug-ins are accessible. In general, the detector will only find animatable parameters on these plug-ins, and in some cases none at all, if the plug-in uses non-standard parameter coding.
You can use the class and object inspector functions in MAXScript to browse through the 3ds Max core and 3rd-party classes accessible in MAXScript.