and :commit for writing changes to the persistant memory
Ctrl+X again
There is a difference in philosophy. In RouterOS you can use "safe mode" to make some changes and they will be rolled back when you lose the connection.
I'm not sure what happens with the changes when you powercycle the router halfway.
In some other equipment any change that you make is only made in memory and there is a separate command like "save" or "write" to
write all changes you made in memory back to the nonvolatile memory device. A powercycle before that will reset all configuration to what it was
when you last saved it. Commands exist to reboot the device (to its last saved configuration) after some elapsed time.
So you can work on the device for a time interval you choose yourself, and when you lose connection you wait until the interval elapses and you
get your connection back with the last saved settings. During your work you can disconnect, it will not affect this thing.
Advantage: you can work e.g. on VPN settings that result in disconnect/reconnect which is not possible in RouterOS "safe mode".
Disadvantage: there is always the risk that you forget to save some change, and months later, when the power is cycled, you suddenly find
yourself back at an older configuration. Of course when you work regularly with such devices you have it wired in your fingers to always type
"write mem" or "save" or click some button whenever you have changed something. But for MikroTik users such a change would be major
and would certainly lead to some frustration and misunderstanding.
There is also another model where you can batch up some changes and then you "apply" them all in one transaction. That is similar to the { commands }
construct in RouterOS. However this is not available in GUI modes (winbox/webfig).