This document provides an overview of acids and bases for an AP Chemistry course. It begins with definitions of acids and bases according to Arrhenius, Brønsted-Lowry, and Lewis theories. It then distinguishes between strong and weak acids/bases, as well as concentrated and dilute solutions. Conjugate acids and bases are defined. Equilibrium concepts such as acid dissociation constants (Ka) and base dissociation constants (Kb) are introduced, and their relationships to strength are explained. The autoionization of water and the water dissociation constant (Kw) are covered. Finally, the logarithmic pH scale is defined.