The answer to 'why is my outlet not working' is that there are several common causes, including a tripped circuit breaker, a faulty outlet, or a wiring problem. The most common symptom is that the outlet has no power and nothing plugged into it will work.
First, check the circuit breaker for the outlet. If it has tripped, simply reset it. If the breaker keeps tripping, there may be an issue with the wiring or a problem with the outlet itself. Next, use a voltage tester to check the outlet for power. If there is no power, the outlet may need to be replaced. If the outlet has power but devices still don't work, the issue could be with the wiring behind the wall. In this case, it's best to call a licensed electrician to diagnose and repair the problem.