* ssh
A program for logging in to a remote machine and for executing
commands on a remote machine. The command is intended to replace
rlogin and rsh, and provide secure encrypted communications
between two untrusted hosts over an insecure network. X11 connections
and arbitrary TCP/IP ports can also be forwarded over the secure
channel.
* sshd
The daemon for Secure listens. This daemon listens for connections from
clients and provides secure encrypted communications between two
untrusted hosts over an insecure network.
ssh-keygen Generates and manages authentication keys for ssh.
* ssh-agent
A program that holds private keys that are used for public key
authentication. ssh-agent is started at the beginning of an X-session or
a login session, and all other windows or programs are started as clients
to the ssh-agent program. Through the use of environment variables,
the agent can be located and automatically used for authentication when
users log in to other machines while using ssh.
* ssh-add
Adds RSA or DSA identities (keys) to the authentication agent, ssh-agent.
* scp
Securely copies files between hosts on a network by using ssh for data
transfer. Unlike rcp, scp asks for passwords or passphrases (if they are
needed for authentication).
* sftp
An interactive file transfer program, similar to ftp, that performs all
operations over an encrypted ssh transport. sftp connects and logs
into the specified host name and then enters an interactive command
mode.