How'S the lifecycle of execution/run time of a program? How long

Then I would say it depends on the engine that runs the code. V8 just-in-time compiles JavaScript, then it executes code in an order defined by the event loop and callstack. https://nodejs.org/en/docs/guides/event-loop-timers-and-nexttick/ programs are as long in an "execution state" as they have listeners that keep the program up and running. But that does not mean it is working all the time. \