# An LLM Is a Conditional Probability Machine: P(x_t | x_<t) and Its Consequences

> Source: https://sukruyusufkaya.com/en/learn/llm-muhendisligi/llm-conditional-probability-machine
> Updated: 2026-05-13T13:00:24.536Z
> Category: LLM Mühendisliği
> Module: Module 4: The Mental Model of LLMs
**TLDR:** Clarify what an LLM is at its core: a machine producing conditional probability distributions. Autoregressive generation, chain rule decomposition of joint probability, real meaning of perplexity measurement, why 'hallucination' is inevitable, calibration concept, relationship between logits and probabilities.