RNA is presently used in cells to transcribe and
carry information -- not as permanent
storage. In other words,
RNA is the flash drive and DNA
is the hard drive.
However, RNA can store genetic
information. That storage is just not
as foolproof or as stable (i.e.,
not for as long) as DNA.
RNA can also be a catalyst -- a molecule
that aids in chemical reactions
without being used up. Presently,
most catalysts are proteins
(enzymes).