, ive never really understood why theres so many different starters, they all look similar inside.
They are for different purposes and have different striking voltages. Series starters are run in series so the striking voltage must be below 120v. They are for 2 tubes in series or single tubes up to 20 w on 120v or 240v systems. You can't use them on longer tubes as the striking voltage is less than the tube running voltage. Standard starters, generally labelled 4 to 65 w have a striking voltage higher that the running voltage of 5 foot tubes. But they can't be used with 6 or 8 ft tubes as once again their striking voltage is less than the running voltage of such tubes. Yet another starter is for those longer tubes.