A dictionary is a book or online resource that provides definitions of words. It helps people understand the meaning of unfamiliar words, how to pronounce them, and how to use them in sentences. Each entry typically includes the word, its part of speech (like noun or verb), and its definition. Some dictionaries also provide synonyms, antonyms, and example sentences. Dictionaries can be specialized, focusing on specific fields like law or medicine, or they can be general, covering everyday language. They are essential tools for students, writers, and anyone looking to improve their vocabulary. Using a dictionary can enhance communication and understanding in any language, such as English or Spanish.