What "Real-Time" Actually Means
"Real-time" is the most abused word in embedded engineering. It is used to mean fast, to mean interrupt-driven, to mean "there is an RTOS in the build", and occasionally to mean nothing at all beyond marketing. None of those is the definition. A real-time system is one whose correctness depends on when a result is produced as well as on what the result is. A right answer delivered late is a wrong answer. That is the whole idea, and everything else on this page is a consequence of it.