真理 (zhēnlǐ) refers to universal, objective truth — the kind found in science, philosophy, or religion. It is broader and more abstract than 真相 (zhēnxiàng, the actual facts of a specific event) or 实话 (shíhuà, truthful words in speech). 理 (lǐ) can also mean 'truth' but as a principle or reason, often in a more concrete or moral sense.