Determinism
In plain terms
The property of always producing the same output for the same input.
Going deeper
A deterministic process gives identical results every time given the same inputs and state, making behavior predictable and testable. No randomness or hidden variance.
Under the hood
Non-determinism (from concurrency, randomness, time) complicates testing and reproducibility.
Examples
Pure functions, reproducible builds, testing, idempotency, predictability.
Think of it like...
Like a vending machine that always dispenses the same item for the same buttons.