AFP and SMB are both full-featured file-sharing protocols with reasonably good security.
NFS is not as secure as the other protocols, but it is very convenient for UNIX clients. Be
careful before you “export” (share) a volume over NFS. With a Mac OS X server and a Mac
OS X client, NFS volumes are browsable in Connect to Server; that is, a user can find them
by browsing through a list of servers in the Connect to Server window.
FTP is useful because it offers maximum compatibility. However, FTP also offers a mini-
mum feature set, and its passwords are sent over the network as cleartext unless you are
using the Kerberos option and a supported Kerberos FTP client—something the Mac OS X
Finder lacks.
Mac OS X supports secure File Transfer Protocol (SFTP), ...