From Longman Business Dictionary
folderfold·er /ˈfəʊldəˈfoʊldər/ noun [countableC]1a cover for keeping loose papers in, made of card or plasticAll the correspondence is in this folder.
2COMPUTING a place in a computer where a group of related FILEs are stored, usually appearing on the screen as a picture of a folderMost programs automatically create a document folder on the desktop.