“Double Action” and “Single Action” can be pretty confusing terms for new shooters. My Wife got confused with the terms for AGES simply because she’s not a gun geek, she’s a shooter. For her cocking the hammer, the firing a revolver was “two actions” leading her to confuse the single-action shot with a “double action”, and she could give a damn about HOW the gun manages to shoot.
“Single Action” and “Double Action” is really just talking about the actions done by the TRIGGER.
And there is a SEA of other actions in between, which really gets geeky, like the fully-charged striker of some Walthers or the Springfield XD, the partially charged striker of M&Ps Glocks, Kahrs and many others. The partially charged hammer like on a Ruger LCR or a SIG DAK trigger.
And I’m sure I’m missing a ton. That being said, while I am amused by the mechanical workings of a gun, when it comes to actually SHOOTING things, I really just judge on feel. Does it feel like a long pull with a bit of tension on it? Does it feel like a short crisp pull? I’ll often simplify those pulls to simply “Double Action” or “Single Action” when maybe that isn’t 100% true.