Need access to a local Linux computer via LAN

Thank you all very much. SSH is exactly what I was hunting for. Thanks.

Next question. When I "ssh -l user ww.xx.yy.zz", I get an error
"The authenticity of host 'ww.xx.yy.zz (ww.xx.yy.zz)' can't be
established.
RSA key fingerprint is (and a whole bunch of xx:xx:xx:...xx:xx:xx.)
Are you sure you want to continue connecting (yes/no):

if I continue (yes) I get

"Warning: permanently added 'ww.xx.yy.zz' (RSA) to the list of known
hosts.

Then it asks for the root password and lets me in.

Reading through the "Red Hat Linux 8 Bible", I find nothing on this. I am
thinking that the (and a whole bunch of xx:xx:xx:...xx:xx:xx.) is part of
the "Secure Connection" associated with SSH and I don't have any security.
Don't really need it as I am behind a fairly secure firewall (or so we
think) so the connection is trusted. But, how should this be done for
security and is there a good reference of this?

Thanks

George Wayne Gambill ... Registered Linux User: #311028