Data

 Each constant, variable, array, expression, or function reference
 in a Fortran statement represents typed data.  The data type of
 these items can be inherent in their constructions, implied by
 convention, or explicitly declared.

 Each data type has a name, a set of associated values, a way to
 denote the values, and operations to manipulate and interpret these
 values.

 There are two categories of data types:  intrinsic and derived.
 The names of the intrinsic data types are predefined and are always
 accessible.  Derived data types are user-defined data types that
 are made up of intrinsic or derived data types.

Additional information available:

Arrays          Constants       Derived_Types   Expressions     Intrinsic_Types
Substrings      Variables