JTB理論係知識論入面對知識嘅其中一種定義，認為知識應該係一種“確證嘅真信念”。具體嚟講，係指若且唯若滿足咗下面呢三個條件嗰陣時，“S知道P”呢一個命題先至可以得以成立：
JTB theory is one of the definitions of epistemology into the face of knowledge, which holds that knowledge should be a kind of uranium confirmatory true belief uranium. Specifically, it means that the proposition "S knows P" can be established if and only if the following three conditions are met: