No LBC - 4WD vs AWD

Please excuse the non-LBC post, but I just want to tap the wealth of
automotive knowledge here.  Can somebody explain to me the difference
between Four Wheel Drive and All Wheel Drive?  Which one is better for the
snow here in Buffalo?  I've always had 4WD, so I don't have the experience
to make a comparison.

Thanks!

-Nory

'74 Midget
'71 Midget parts car
'94 4WD Ford Ranger
'95 4WD Chevy Blazer
'91 4WD Jeep Cherokee
3 cats
1 dog
1 gun