The first snippet of code declares a variable named '@array'. The second snippet of code declares the variables named by the elements of @array, whatever they may be.

#!perl -w

use strict;

use vars qw(@array);
# same as: use vars '@array';

BEGIN {
  # the use vars below happens at compile time,
  # so @array must be set at compile time
  @array = ('$scalar', '%hash');
}

use vars (@array);
# $scalar and %hash are now declared

$scalar = 7;
%hash = (key => 'value');
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qw/STRING/ is actually the same as split ' ', 'STRING'.