The Abhidhamma Pitaka (abhidhammapiṭaka) is the last of the three pitakas (Pali for "baskets") constituting the Pali Canon, the scriptures of Theravāda Buddhism.
The Abhidhamma pitaka is a detailed scholastic reworking of material appearing in the Suttas, according to schematic classifications. It does not contain systematic philosophical treatises, but summaries or enumerated lists.
Read more about Abhidhamma Pitaka: Translations, Nature of Abhidhamma, Origins, Contents, Place in The Tradition