What are No Load And Locked Rotor tests on a three phase induction motor?

Doing a No Load test of a 3-phase induction motor involves the measuring of current, voltage, torque etc with no load on the rotor shaft, meaning that it is free to turn but is not driving anything else.

Similarly a Locked Rotor test involves the measuring of current, voltage, torque etc with the rotor shaft "locked" i.e. prevented from turning, which is the worst loading condition the motor would ever have to contend with.