Pinking, detonation and pre-ignition are 3 different things
Pre-ignition is when the mixture self combusts before the plug fires (dieseling basically), usually caused by a hot spot in the combustion chamber, glowing bit of carbon on an exhaust valve or something.
Pinking is caused by over advanced ignition timing combusting the mixture before the pistons at TDC. This is what happens when you try and drive up a hill in 4th gear at 1500rpm.
Detonation is when the 2 flame fronts collide with each other. What happens here is the plug fires and starts a flame front but the end gas self combusts and the 2 fronts meet each other and bang.