This document provides an overview of the classification of organisms. It begins by outlining the basic competencies around classifying living and non-living things. It then discusses the key characteristics of living organisms, including movement, respiration, nutrition, growth, reproduction, excretion, irritability, and adaptation. The document proceeds to discuss the history of classification from Aristotle to Linnaeus to Whittaker's five kingdom system. It provides details on the kingdoms of Animalia, Monera, Protista, Fungi, and Plantae. Within each kingdom, it outlines the major groups and provides examples.