This document summarizes key concepts in morphology. It begins with definitions of morphology and morpheme. It then discusses the different types of morphemes - free morphemes, which can stand alone as words, and bound morphemes, which cannot. The document also covers different types of bound morphemes and provides examples of affixes. It explains concepts like assimilation, dissimilation, epenthesis, metathesis, and language variation. Examples are given for each concept and they are defined in 1-3 sentences.