Heat Pump Question

Hello all, I am new, just stumbled upon this site looking for answers to
my confusion.

Just bought a home 2 months ago, in upstate NY, this is our first home.
The home was built in 1979, and everything in it seems to be original to
that date. (and I mean everything) I have several sources of heat, oil
furnace for the most of the house, and electric baseboard and fire place
for the living room portion of the house on a slab (an addition made I
assume).

My issue is this York heat pump located in the basement.  It is connected
to the duct work of the oil furnace.  I know very little so I've been
trying to figure out its use.  So far I've read that it works with a ac
unit that should be outside.  There is a cement platform outside and what
looks like connections on the outside wall of the house next to this that
seemed to have been for a central air unit(again, I know little).  

My question would be, is this York Champion & Sunpath Heat Pump a unit
that I can use stand alone for heat (either as a supplement or a backup to
my furnace) or does it require an outside unit to function.  If yes is it
an efficient alternative to fuel?  

When we first moved in I turned on the thermostat for the heat pump, and
im sure heat was coming out of the vents, it could have just been warmer
air. Any help would be appreciated.  Thanks

Jay.
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