This document discusses the composition and structure of meat. It states that meat is composed primarily of water (75%), protein (20%), and fat (up to 5%). The structure of meat is determined by muscle fibers bound together by connective tissue. Aging meat involves holding it in coolers for an extended period of time to naturally tenderize it. There are two main aging methods - wet aging which involves vacuum packing smaller cuts, and dry aging which exposes the meat to air on all sides without packaging. The document also provides an overview of variety meats, also known as offal, which are organs and glands not part of the dressed carcass.