The Maya API uses a convention of prefixes on its classes to distinguish the various types of C++ objects that it uses.
MObjects much the way a function set does. For example, MItCurveCV is used to operate on an individual NURBS curve CV (there is no MFnNurbsCurveCV), or iteratively, on all the CVs of a curve.MObject is a handle on Maya’s internal objects, and MGlobal is a class of static methods that operate globally and do not require an MObject on which to operate. (See Selecting with the API for information on MGlobal.)