Scenes allow you to automate a sequence of events and actions and to then initiate them from by a single action or event. They are the home automation equivalent of a computer macro. The scenes used in our Home Control System can be run by incoming events.
A scene can also be initiated or triggered manually. It might be the push of a switch or a button on a remote control. We are not prescriptive and it could be a user command that causes the scene to be run.
We don't use these much but, scenes can also be scheduled to run at regular intervals.
We manually trigger a 'guests arriving' scene to make out home more hospitable and look more welcoming when we have guests arriving. This scene switches on some of our front lights and switches off things like our cat scarers. Our contextual smart home will also notify us when they arrive.
Our contextual smart home can automatically run a 'perimeter check' scene when it thinks it is necessary (it can also be manually initiated) and this checks various sensors for activity, enables external lighting and operates security cameras.