This document provides an introduction to comparative politics. It discusses what comparative politics is, what it studies, and its main approaches. Comparative politics aims to describe, explain, and predict outcomes by comparing political systems, institutions, actors, and processes across countries. It examines similarities and differences at the national, sub-national, and supranational levels. The document also outlines the evolution of the field from its traditional focus on institutions to the behavioral revolution examining public attitudes, and more recent returns to institutional analysis.