There are 4 different types of triggers that you should know about. But more importantly, you must know how they work so that you don’t get confused.
Let’s use the double action only trigger as an example. This trigger system is very disliked by people who fancy a light trigger with little to no movement. This is considered to be one of the safest trigger systems, though. You will find this trigger on a pistols like Glock, Kahr, and the XD. The DAO triggers are only the same in principle of using the long trigger pull to build momentum. This is seen to be safe and also give a long and reliable service life by minimizing tension on the striker spring until it is in use.
Many people who like Glocks and several other striker fired pistols, will dislike the Kahr trigger even though they are both DAO. Though the Glock and Kahr triggers perform the same task, the way in which they go about it is quite different. Not all DAO triggers are bad and unusable. It is all about how the pistols are designed to fulfill their role.