In most cases it doesn't matter, but it causes extra pain when you want to write a function that accurately needs to know "do I have a filehandle", like in File::Copy:

    my $from_a_handle = (ref($from)
                         ? (ref($from) eq 'GLOB'
                           || UNIVERSAL::isa($from, 'GLOB')
                           || UNIVERSAL::isa($from, 'IO::Handle'))
                         : (ref(\$from) eq 'GLOB'));
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