Saving
A typical ship's sensor configuration can get quite complicated and large. As when editing things in a word processor, saving often is a good idea.
When you start making changes to your configuration you will notice the main toolbar turn to a reddish color and display text alerting you to the fact you have unsaved edits.
If you go to lunch, sleep, etc or even close the browser your changes will not be lost. They are kept in memory on the server itself. The next time you load CFE you will see the same screen with the same warning. However, in the event the server itself is rebooted (patches, etc) then any unsaved edits you have made are at risk.
To save your sensor configuration simply click Save from the Configuration dropdown located in the main toolbar or click the Save Changes button directly. Once you have saved your changes they are serialized to persistent storage and will survive even the server being rebooted. This also sets a hard state you can roll back to if down the road, after many other edits, you wish to abandon them and revert back.
Once you have saved your changes the main toolbar will update itself to a yellowish color and the text will reflect your new state. Your changes are now saved to the database, but they are not yet published and actively being used by clients.
Any changes you make are completely independent of the running SCS system (ACQ, Events, clients, etc). You can edit and save repeatedly for as long as you wish without effecting anything but CFE.
Once you are happy with your changes you can make them live by publishing them; or if you wish you can abandon them by clearing the config and loading the last publish.