A compendium is a concise collection of information or summaries on a specific subject. It serves as a reference tool, providing essential details in an organized format. Compendiums can cover various topics, such as science, history, or literature, and are often used by students, researchers, and professionals to quickly access key facts. These collections can take many forms, including books, articles, or digital resources. A well-known example is the Compendium of Materia Medica, which compiles traditional medicinal knowledge. Compendiums are valuable for their ability to distill complex information into easily digestible formats, making learning more efficient.