The plain-English version
The elapsed or scheduled time interval supplied to an update, used to express rates independently of update count.
Why it matters
It lets you describe motion in units per second rather than arbitrary units per displayed frame.
Let’s make it click
For simple non-physics motion, a character moving three units per second advances by speed multiplied by elapsed seconds.
Vibe Bro’s heads-up
Blindly multiplying every calculation by delta is incorrect; some engine APIs already accept velocities or handle time internally.
The docs behind it
Documentation links checked .
Editorial review · October 28, 2026
Supported: The rate-times-seconds example is correct for simple movement. The caveat about APIs that already handle time prevents applying delta twice.