To send a remote command via SSH (the SSH server needs to be running on the remote host), you can simply write the command after user@machine.

ssh [email protected] echo 'Hello World'

Hello World

It returns back the output to the sender, executed on the remote host.

Many commands and programs in the remote side are screen-based (e.g. mc) or they need to ask password (e.g. sudo), to be able to run these kind of programs you can use option -t.

ssh -t [email protected] sudo ls /

[sudo] password for alice:

bin root dev etc home lib mnt opt proc root run usr var