I see references to SFTP and FTPS.  Are these the same or are they different?  If they are different, what is the difference?

SFTP and FTPS are two different protocols.

FTPS (also known as FTP Secure and FTP-SSL) is an extension to the commonly used File Transfer Protocol (FTP) that adds support for theTransport Layer Security (TLS) and the Secure Sockets Layer (SSL) cryptographic protocols. 

SSH File Tranfer Protocl (SFTP), an incompatible secure file transfer subsystem for the Secure Shell (SSH) protocol. It is also different from Secure FTP, the practice of tunneling FTP through an SSH connection.