Smokes coming from back wheel

Hi!
Bought my first car week ago so dont know about cars much at all.

I had smokes coming from right back wheel,wheel was heated but not flaming hot after driving 1 mile 30-40mph. After i stopped and inspected I couldnt see anything rubbing, I drove 2 more miles and checked again and wheel was cooling down.
Wheel seems to be rolling fine, not sure what to look at now or what action to take as problem seems to be gone now.
It is Citroen Xsara picasso 2005 with 74k miles on it.

Thanks
Janis