In addition to creating new text documents in the content editor (with word processor-style formatting), people can upload documents as files of other types, including PDF files, Word documents, spreadsheets, and other file types. You can configure how uploaded documents are handled using the admin console.
Admin Console: System > Settings > Documents
Uploaded documents can add up in size. If this becomes an issue, you can limit the size of uploaded files or disable file uploads altogether.
If you enable uploaded documents, you can disallow content types that you don't want people to upload. You can also add MIME types that aren't in the current list.