This document discusses the usage of dictionaries. It defines lexicology and lexicography as the study of vocabulary and dictionaries. It describes dictionaries as references that list words alphabetically and provide meanings and other information. The document outlines the macrostructure and microstructure of dictionaries, including sections, headwords, definitions, and other elements. It also discusses different types of dictionaries for topics, languages, themes, and educational levels. Finally, it provides examples of tasks for using dictionaries, such as finding words, translations, and definitions.