Oversteer
Oversteer is when the rear tyres lose grip first and the back of the car steps out, rotating it more than the driver asked for.
Caught early it is quick — a car that rotates willingly can be pointed out of a corner sooner. Caught late it is a spin, which is why it is the imbalance that punishes hesitation.
Drivers differ sharply in what they want. Some are fastest in a car with a loose rear; others lose confidence and time in the same machine. A large part of team-mate comparison is really a comparison of what balance each has been given.