A three-ring binder is a type of folder used to organize and store loose sheets of paper. It features three metal rings that hold punched pages securely in place. Binders come in various sizes, typically ranging from 1 inch to 3 inches in width, allowing users to choose the capacity that best fits their needs. These binders are commonly used in schools, offices, and homes for organizing documents, reports, and notes. They can also accommodate dividers and sheet protectors, making it easy to categorize and protect important information. Many people personalize their binders with covers and labels for easy identification.