Originally Posted by S1

Someone correct me but this is what I remember from my college course-

Pinking - When the ignition is too far advanced, the mixture ignites before the piston has got to TDC and is effectively slowing it down - Gives a tinkling sound. If youve ever been in an old Mk Festa 1.1 then you've probably heard it.

Pre-Ignition - Similar to above but generally caused by carbon deposits in the combustion chamber which glow red hot and ignite the mixture early like in pinking.

Detonation - Caused by excessively high combustion chamber temps or pressures. The mixture is exploding rather than burning/expanding in a controlled way. Leads to even high temps and melted pistons etc