It was once the case that technical documentation came in bound books. Yes, those large books that no one ever reads.The podcast I'd Rather Be Writing takes a look at the traditional wisdom of documentation and compares that with documentation in an Agile development context. It is argued that
some agile environments move so fast, you have to triage what you document because there’s no time to document everything.The point is that not only is there not enough time to document everything, you shouldn't document everything because "you end up giving everything equal importance and losing focus on the key tasks and concepts users need to learn". The recommendation by I'd Rather Be Writing is that everything should be documented somewhere, but the user should be presented with quick references and tutorials that focus their attention to the most important aspects.
This is a fine approach, but rather outdated. Minimalism and Information Mapping have been furthered by technological advances. It is now possible to write in a strictly topic-based style that offers little narrative verbiage (or context), but gets the user directly to the relevant information. Discrete topics can direct the user to the necessary information through sophisticated information retrieval technologies: semantically-rich search, and ontologies for browsing.