A file folder (US usage) (or folder in British and Australian usage) is a kind of folder that holds papers and money together for organization and protection.[1] 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. Files may also contain other things like magazines, cased in music CDs, etc. sometimes mostly not used for any official use, rather used as normal storage in a home. They are often used in conjunction with a filing cabinet for storage. File folders can easily be purchased at office supply stores.
File folders are usually labeled based on what is inside 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 label makers that can be used to make the labels.
via wikipedia