Originally posted by seraphim
/msg is just an Alias used by the IRC Client.
The Original Message is:
/raw PRIVMSG nick|#chan text
/msg nick|#chan is just an alias.
And just to be pedantic, the /raw command is ANOTHER alias in most clients.
The ACTUAL command sent by the client to the server in the IRC stream is "PRIVMSG <target> :<message>" where <target is either a nick, a channel or a comma (,) seperated list of either or both and <message> is the actual message.