Morphology is the branch of linguistics concerned with the structure and form of words in a language, including the study of morphemes, which are the smallest units of meaning. It explores how words are formed, how they relate to other words in the same language, and how they convey meaning.
A morpheme is the smallest grammatical unit in a language that carries meaning or a grammatical function. Morphemes can be free, standing alone as words, or bound, attaching to other morphemes to modify meaning or function.