Async documentation
Async documentation is the body of writing that lets a distributed team decide and progress without overlapping in time. It captures the decision and the reasoning behind it, not just the conclusion, so someone arriving months later understands why it was done that way.
Its real function is to avoid meetings, not to accompany them. A well-written decision document includes the context, the alternatives rejected and why they were rejected. Without that, teams rerun the same debates every few months because nobody remembers what was already tried.
Also called: internal documentation, knowledge base, decision log