This document discusses different types of dictionaries and how to effectively use a dictionary. It outlines that there are bilingual dictionaries that translate between two languages, monolingual dictionaries that define words within one language, and specialized dictionaries focused on areas like phrasal verbs, Spanish cognates, or technical terms. The document recommends that when using a dictionary, the reader should check all meanings of an unfamiliar word in context, look up translations of foreign words in an English dictionary, write notes to review word meanings, and first guess a definition before confirming in the dictionary.