SSH stands for Secure SHell. It's basically Telnet with encryption, but it's a whole lot more. It allows you to forward ports through the encrypted tunnel that it creates and it has some cool tools associated with it such as: scp, sftp, etc. Too many cool things to talk about here, so read the man page and ask me to do some examples for the next LUG if your interested.

sshfs allows you to mount the filesystem from a remote machine running ssh to your local machine. This would allow you to do things such as remotely and securely backup your important files (or better yet, just work off of your remote copy), listen to your home music collection from a remote location, etc. It's very handy and pretty secure.