When you have an important file you want to retain for your records, you can link the file, from whatever you use to store and share your files currently, e.g. Google Drive, Dropbox, OneDrive, etc., to a Company. For instance, you want to keep a quote you provided to a company, or you want to hang onto a credit application for a new customer so you don't have to ask for the information when they buy from a second or third manufacturer you represent.
The best place to keep a link to the file is in Companies. Read on to learn how.