Vocabulary is important for communication and comprehension. It involves studying word meanings, usages, and roots. There are various ways to present new vocabulary, such as definitions, descriptions, examples, illustrations, and contexts. Practice and review are also important to consolidate learning and turn passive into active vocabulary, using techniques like games, semantic mapping, and regular review. When introducing new words, teachers can present meaning first then form, or form first then meaning, using tools like pictures, objects, or gestures.