Difference between potentiometer and voltmeter

Potentiometer	Voltmeter
Potentiometer measure emf of cell very accurately.	Voltmeter measure emf of cell approximately.
Potentiometer does not draw any current from known emf source while measuring current.	Voltmeter draw current from known emf source while measuring current.
While measuring emf, resistance of potentiometer become infinite.	While measuring emf, resistance of voltmeter becomes very high but measurable.
In the potentiometer sensitivity is high.	In the voltmeter sensitivity is low.
It is based on null deflection method.	It is based on deflection method