What exactly is the difference between these things and furthermore, what does
postUpdate do in this context.
I got to this question when I noticed that the rule
Switch HueScene_1 "Sunset" (Scenes)
rule "HueScene_1" when Item HueScene_1 received command
is not executed when the item is in state
ON and you send a PUT request via the REST API to
/rest/items/HueScene_1/state to state
ON. However, clicking the button on the OpenHAB website will cause the rule to execute, even if it the scene is still active.