Cylinder – Combination of the Same Tracks on Different Discs
Cylinder refers to the combination of the same tracks on different discs. The number of turns of concentric circles (track) on disc is the number of cylinder. These tracks have a same magnetic filed rotating direction. If there is a dead pixel on one track, the track will be abandoned, because this track can't constitute a path. This is just like the situation where a piece of wire is broken down in series circuit.
Tip: Have you heard cylinder alignment on hard disk partition? This way is used in older OS versions like Windows XP and Windows Vista. MiniTool Partition Wizard enables you to align to Cylinder when creating a partition.