A file foler (US usage) or folder (British and Australian usage) is a kind of folder that holds loose papers together for organization and protection. File folders usually consist of a sheet of heavy paper stock or other thin, but stiff, material which is folded in half, and are used to keep paper documents. They are often used in conjunction with a filing cabinet for storage. File folders can easily be purchased at office supply stores. In the UK, one of the oldest and best known filing companies is Railex. File folders are usually labeled based on what's inside of them. Folders can be labeled directly on the tab with a pen or pencil. Others write on adhesive labels that are placed on the tabs. There are also electronic labelmakers that can be used to make the labels.