A "phrase" is a group of words that work together to convey a specific meaning. Unlike a complete sentence, a phrase does not contain a subject-verb combination and cannot stand alone. Phrases can serve various functions in a sentence, such as acting as a noun, verb, or adjective. Common types of phrases include noun phrases, verb phrases, and prepositional phrases. Phrases are essential in language as they help to add detail and clarity. For example, in the phrase the tall building, "the tall" describes the noun "building." Understanding phrases is crucial for effective communication and enhances both writing and speaking skills.