What is the main feature which determines whether the engine is either a coil per plug conventional distributor or DIS system?

The main feature that determines whether an engine uses a coil-per-plug conventional distributor or a Distributorless Ignition System (DIS) is the arrangement and number of ignition coils. In a coil-per-plug system, each spark plug has its own dedicated ignition coil, providing efficient and precise spark delivery. In contrast, a DIS typically uses fewer coils to serve multiple spark plugs, often relying on a waste-spark design. This difference in ignition coil configuration directly influences the engine's performance, efficiency, and reliability.