Does OpenSSH use RCP?

I know the question sounds silly, but I have been having a discusion
with someone about the difference between OpenSSH and SFTP. In my
experience I have found that using SCP to transfer files actually uses
the SFTP subsystem. Am I correct in thinking this? The reason I came
to that conclusion is, if a system does not have SFTP configured
properly (i.e. sshd_config file not pointing to the correct location of
SFTP) than SCP will fail. This has lead me to believe that running SCP
actually uses SFTP to some degree.

Or am I missing something?

Either way, this discussion has brought up the difference between using
SCP and SFTP to move files. The person I am having a hard time
agreeing with is telling me that Openssh uses the RCP protocol.

*boggle*

Anyone ever heard of such a thing? This makes no sense to me, as every
system I have OpenSSH running on does not have any of the 'R' commands
configured (inetd.conf doesnt even start the services, so RCP fails)
and the whole point of using SSH is to replace the R commands (rcp,
rsh, etc....)

.