Every test, by what it is about: the unit tests and scenarios, the Python and JS tests of the scripts and the web pages, and the checks with what each last found. Pick a subject, a module or a part of the system, to read its tests: what each one proves, where it lives, and the command that runs it. A scenario lists its steps, with the contract it is held to and the range it was observed in on each board. The strategy behind them is Testing strategy.