In brief, roll center is a way to measure how eager the car is to lean into turns. If you lower the car’s roll center, its chassis will roll side-to-side more, and that transfer of weight to the outside wheels creates extra grip on that side.
Lower front roll center
Higher front roll center
Lower rear roll center
Higher rear roll center
Changes to the lower suspension arm typically have a larger impact than changes to the camber link.
The roll center is affected by many different changes to the suspension, including camber link length, camber link ball stud locations, arm length, pin height, axle height, and others.