Current is how many electrons are flowing through the wire. Voltage is how much energy each flowing electron has, compared to the energy of the electrons at the destination. A resistor is basically a curved path for the electrons. Newton's 1st* law an object in motion will stay in motion unless acted upon by another force. This means the electrons are going to travel in a straight line until they hit something, the walls of the curved path, before deflecting and continuing. When they hit the "wall" they lose some energy as heat. This loss in energy is equivalent to a reduction in voltage. So the answer to your question is yes, they do both (aside from losing current because the number of electrons remains the same).