API Guide > Maya API introduction >

# Naming Conventions

The Maya API uses a convention of prefixes on its classes to distinguish the various types of C++ objects that it uses.

- MFn - Any class with this prefix is a function set used to operate on MObjects of a particular type.
- MIt - These classes are iterators and work on 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.
- MPx - Classes with this prefix are all Proxies, API classes designed for you to derive from and create your own object types.
- M classes - Most of these classes are Wrappers, though there are others. For example, Function sets 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.)