An encrypted transfer is a file transfer that is protected by end-to-end encryption. This means that the files to be transmitted are fully encrypted in the browser before they are uploaded. End-to-end encryption thus provides additional security during file transfer.
If you receive an encrypted transfer, you will need the password from the sender. Without it, you will not be able to download the files. Depending on the settings chosen by the sender, however, the password may already be embedded in the link and will be read automatically when the link is opened.