There are two ways to use a command line to start an application on another system:
Using rlogin
Using remsh
When you use rlogin, you use your terminal emulator to log in to a different (remote) system. You then run the command to start the application on that system.
Use the rlogin command to log in to the system containing the application.
rlogin remote_system_name
For example:
rlogin systemA
Type the command to start the application. Use the -display option to send the window back to your display.
For example, assuming your own system's display name is MySystem:0:
/usr/bin/X11/xload -label systemA -display MySystem:0
The term remsh stands for "remote shell." It provides a one-step way to run an application, since you do not have to log in before running the command.
Type the command:
remsh remote_system_name -n command
The command must include the -display option to send the window back to your display.
For example:
remsh systemA -n /usr/bin/X11/xload -display MySystem:0