folder

Short definition from Wiktionary

Noun

1. 1
   An organizer that papers are kept in, usually with an index tab, to be stored as a single unit in a filing cabinet.
2. 2
   A virtual container in a computer's file system, in which files and other folders may be stored. The files and subfolders in a folder are usually related.
3. 3
   A machine or person that folds things.
4. 4
   A folding knife, typically a pocketknife.