Why should I use 4-wire ohms versus 2-wire ohms?

Why should I use 4-wire ohms versus 2-wire ohms?

A 4-wire ohms measurement bypasses the voltage drop in the test leads by bringing two high impedance voltage sense leads out to the unknown resistance. With very little current flowing into the sense leads, the voltage seen by the sense terminals is the same as the voltage developed across the unknown resistance.