In sharp contrast to Java's docs are Android's terrible docs. As a Java programmer, I had assumed Android's docs and behavior would be of equally high quality. But time and again, Android's platform had a a way of springing surprises that weren't documented anywhere. More than a decade has passed but the activity lifecycle's behavior and docs remain as ambiguous today in 2022 as they were in 2010!
- A quick and easy interactive tutorial to teach you the absolute basics: $ vimtutor. No prerequisite whatsoever.
- An extensive tutorial that takes you from noob to wherever you want to go in a gentle and iterative way, the user manual: :help usr_toc. This one is pretty much the natural next step after vimtutor if you ever want to use Vim efficiently. Too many people think they are smart enough so they skip it. They are wrong. Even vimtutor is not a prerequisite.
- A heavily cross-linked reference that covers literally everything, the reference manual: :help reference_toc. This one can be anything from extremely detailed to very terse. You get there when you are not sure about something are to take a deep dive on a specific subject. In general, this part of the documentation makes more sense if you went through the user manual first.
The Postgresql documentation is good enough to teach someone SQL from scratch.