Determinism means repeatability. Give the system the same question under the same conditions and you get the same result. The logic is defined, not sampled.
Most large language models are probabilistic by nature, which is powerful for open-ended language but risky where consistency and accountability matter. The strongest enterprise designs combine the two: a deterministic backbone of rules and structured knowledge that keeps the generative layer honest and repeatable.
This pairing is what lets an organisation stand behind a result and reproduce it on demand.