Binary Troubleshooting is a method used to solve problems.

To start: imagine your problem as a system. Divide the system into 2 equal areas & implement tests to prove the problem is not in 1 of the 2 areas.

Continue: divide the remaining piece of the system where the problem is now proven to exist, into 2 more pieces.  Implement tests to isolate the cause of the problem to just 1 of the remaining pieces. Rinse & repeat.

Stop: when you find the cause of the problem. If your problem were to consist of over 1 million possibilities, it would only take you 20 steps: to find the root cause of the problem.

This divide & conquer process comes in handy, especially when working on projects in unfamiliar terrain.