Remote login is one of the most popular Internet applications. Instead of having a hardwired terminal on each host, we can login to one host and then remote login across the network to any other host (that we have an account on, of course).
Two popular applications provide remote login across TCP/IP internets.
Telnet is a standard application that almost every TCP/IP implementation provides. It works between hosts that use different operating systems. Telnet uses option negotiation between the client and server to determine what features each end can provide.
Rlogin is from Berkeley Unix and was developed to work between Unix systems only, but it has been ported to other operating systems also. ...