Basically,
The series 80 has a mechanical firing pin block consisting of 2 levers in the frame and a plunger and spring in the slide.
When you pull the trigger, the trigger bow moves 1 lever against another lever that pushes up the plunger tube in the slide which allows the firing pin to go forward.
If you don't pull the trigger the firing pin cannot move forward and strike the primer. It is blocked by the plunger in the slide.
I believe the series 80 was introduced in the early 80's.
The series 70 does not have this.
All 1911's have a grip safety. When depressed, the grip safety allows the trigger bow to move back and release the disconnector/sear . When not depressed, the "nub" on the grip safety prevents the trigger from moving back.
All have a thumb safety that when engaged, blocks the sear from moving and the slide from retracting.
The disconnector is a safety, of sorts, but it's not something a user actively engages.
That's the best I can explain it to the best of my knowledge. Other's can correct or enhance.