Remote access and command execution on unix platform

How can we create new directory/Or execute command on remote unix machine from another unix machine.

We can use SSH command to execute command on remote machine but problem is that ssh will prompt for password before executing command.
My requirment is to execute command without manual intervantion.

Thanks and regards
Kunal

rsh or ssh .

You can use ssh without passwd

refer bellow for password less ssh login

SSH login without password