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:
 * ../AppleEvents
 * ../AppleScript