module

   Represents a single compilation unit. You can list the modules
   with the SHOW MODULE command. Each module shown represents a
   single compilation unit - the smallest piece of source that can
   be separately compiled. Even if several of these are compiled at
   once (which is common in languages such as FORTRAN and BASIC),
   each compilation unit appears separately.

   In the query language, SYMBOL=MODULE specifies a certain type
   of symbol. This is not the same as a compilation unit. You can
   have modules which are not compilation units, and compilation
   units which are not modules. How a module is defined varies from
   language to language.