The only explanation I see missing here is how you might build any of these data structures and how to access the data you put into it.

# Declare an array and print out two elements
my (@a) = qw( foo bar baz buz );
print join(", ", $a[0], $a[2]), "\n";


# Declare a reference to an anonymous hash and print
# out some data from it
my ($b) = {
  'foo' => 'bar',
  'baz' => 'baz'
};
print join(", ", $b->{'foo'}, $$b{'baz'}), "\n";


# The following statement is quite odd.
my (@c) = [ 'foo', 'bar', 'baz', 'buz' ];

# Perhaps you meant the following:
my ($c) = [ 'foo', 'bar', 'baz', 'buz' ];
print join(", ", $c->[1], $$c[3]), "\n";


# Create a regular hash and print out some data:
my (%d) = (
  'foo' => 'bar',
  'baz' => 'buz'
);
print join(", ", $d{'foo'}, $d{'baz'}), "\n";
[download]

Note that in the 2nd and 3rd cases I presented, there are 2 methods of accessing the data within the structure. You can either double the dollar sign ($$b{'baz'} or $$c[3]) or use the dereferencing characters ($b->{'foo'} or $c->[1]).