Real-time

A real-time system is one where getting the right answer too late counts as getting it wrong. It isn’t about being fast on average: it’s about being predictable, so every task finishes before its deadline, every time, even in the worst case. Engineers achieve this with careful scheduling, bounded loops, no surprise memory allocation or garbage-collection pauses, and often a real-time operating system that guarantees which task runs when. In “hard” real-time, like an airbag or a flight controller, a single missed deadline is a failure; in “soft” real-time, like video streaming, a late frame just looks a bit worse.