For some componenets, as the currrent through them is changed, the resistancce of the component changes as well
The resistance of ohmic conductors (e.g. a wire or a resistor) doesn't change with the current
At a constant temperature, the current flowing through an ohmic conductor is directly proportional to the potential difference across it (R is constant in V=IR)
The resistance of some resistors and components does change, e.g. a diode or a filament lamp
When an electrical charge flows through a filament lamp, it transfers some energy to the thermal energy store of the filament, which is designed to heat up
Resistance increases with temperature, so as the current increases, the filament lamp heats up more and the resistance increases
For diodes, the resistance depends on the direction of the current
Diodes will let current flow in one direction, but have a very high resistance if it is reversed
