IN DIRECT CURRENT CIRCUITS, RESISTANCE IS A SIMPLE THING. THIS CAN BE EXPRESSED AS A number, from zero to large values, increasing without limit through the millions, and even trillions of ohms. Physicists resistance is a scalar quantity, as it can be expressed on a 1-dimensional scale. Actually, direct current resistance can be represented along a half line, or ray, as shown in the Figure given below.
Figure-- Resistance can be represented on a ray.
Given a certain direct current voltage, the current decreases as resistance increases, in accordance with Ohm's Law, as you know already. The same law holds for alternating current through a resistance, if the alternating current voltage and current are both specified as peak, peak to peak, or RMS values.