If it's a Master system as used on Chubb or Butters detainers, each individual lock has its own key which lifts the detainers to a position where the lock will open, and the detainers have additional notches or slots to suit the Master key at a different height, and each lock has these Master notches at the same height, as well as its own notches to fit its own key. The 3G110 is an example. As these locks are complex and expensive, they are not widely used on domestic homes and do not meet the latest BS. However Insurance companies may accept them as suitable if notified in advance (mine did). You will often see this range on High Street bank branches that still have wooden doors. If you get one, don't lose the key because it is unusually difficult to pick.
This method doesn't work with ordinary lever locks, which work differently and have a gate rather than slots or notches.
With cylinders having pins, instead of a single pin in each position, which has only one break at the height the key will lift it, there are two (or more) shorter pins, so there are two (or more) heights at which the cylinder will turn.
There have been many ingenious designs and inventions, so there is a chance you will come across some other method, but I don't know of any on the market.