Common terms

passwords
kerberos password is the one you use to telnet, to authenticate
(get tickets and/or tokens), and to read e-mail (usually)
local passwords are specific to a particular machine, and do not
have tickets. These are used for FTP, and should be
different from kerberos passwords
local disk
files kept on local disk are directly on the hard drive of the machine, i.e. /usrg0/bovik.
AFS
files kept in AFS are available on all SCS machines, and are kept on central servers.
Your AFS home directory is /afs/cs.cmu.edu/user/username.
maildrop
Your maildrop machine is the machine your mail is recieved on, before
you read it. All mail sent to you in SCS will be forwarded to this machine,
and your mail client will retreive mail from it.

Next: Setting Up