This document provides an overview of key concepts about acids and bases from sections 18.1 through 18.4. It introduces the Arrhenius, Brønsted-Lowry, and Lewis models of acids and bases. It describes the properties of acids and bases and how pH and pKa/pKb values relate to acid and base strength. Neutralization reactions between acids and bases are discussed along with acid-base titrations and buffered solutions.