The classical discussion names seven familiar kinds: first principles, external sense perceptions, inner awareness, propositions with their immediate proofs, experiential judgments, intuitive insights, and massively transmitted reports. They differ in the way assent is produced.
First principles become evident once their meanings are grasped. External senses concern seeing and touching; inner awareness concerns one's present states. Some propositions carry an obvious middle term. Experience involves repeated observations, intuition a swiftly recognized connection, and transmission a convergence of independent reports.
The sevenfold list is a useful map rather than a guarantee that all thinkers place every category at exactly the same epistemic level. Whether a given category is strictly immediate, inferential in disguise, or dependent on conditions remains a further question.