AEDesc (in the Carbon.AE extension) is a wrapper for the C type of the same name. An AEDesc is a (mostly) opaque data structure that represents an Apple Event Descriptor and encapsulates the related methods. Note that raw access to the ../FourCharacterCode representing the AEDesc type is available through the type attribute, and the raw data stored by the AEDesc is available from the data attribute, but you should only use data for simple value types and use coercion and/or the accessor methods on anything else.
See also: