In addition to arrays, hashes, and scalar references you also have:

1. subroutine references.
2. typeglob references.
3. references to lists (distinct from references to arrays).
4. IO references.
5. LVALUE references.

one distinguishing feature of Perl, not available in C involves DYNAMIC creation of data structures and prevents excessive typing, this feature is called Autovivification, in reference view, a reference springs to existence if it is dereferenced under the assumption that it exists. With this in mind, you would notice that Perl references and C pointers are not exactly the same.

EXAMPLE: (Note the reference is held in the scalar value $reference!)
$$reference=5;           #Dereferencing before creating a reference.
print "$$reference\n";   #Creation of $reference autovivifically.
print "$reference\n";
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