This document summarizes the classification of protozoa. It defines protozoa as microscopic, eukaryotic, unicellular organisms. Protozoa are classified into 7 phyla, with the most common human pathogens belonging to the phyla Sarcomastigophora and Apicomplexa. The document provides examples of genera and species within these phyla, including Entamoeba histolytica, Giardia lamblia, and Plasmodium falciparum. It describes key characteristics of protozoa such as locomotion, digestion, and reproduction.