No problem, and in this case we’re dealing with multiple terminologies. Z wave has one set, zigbee has a different set, and smartthings has yet again a different set. And sometimes they use the same words to mean different things, which can be very confusing. 
Since you have a strong technical background, you might want to take a look at the technical welcome FAQ:
http://thingsthataresmart.wiki/index.php?title=Welcome_FAQ
As I mentioned, I rely on text to speech, so I can’t read the actual DTH for the device in this thread (trust me, you don’t want to listen to groovy 
). But if it has “capability.button” then in a smartthings context it will be treated as a “button controller,” Which means that smartapps and routines that allow you to specify “when button is pressed” can respond to the events of this device.
That’s a smartthings platform construct. You can have devices of many different protocols using different clusters or commandsets to fill-in the “button” values. Including a switch that uses double tap if it has the button capability.
You can use a button press to Turn on a single light, change the mode, start a routine, trigger a smartthings scene, it just depends on which automation you are using to process the button event.
Scenes
As far as “scenes”…Pretty much every home automation system has something they call “scenes” or “like scenes”. It just means the ability to set multiple devices to different states with a single request. It’s often limited to lighting devices, but it means you could have one light turn on, another light turn off, a third light be blue at 25%, A fourth light be orange at 75%, etc., and fire them all from a single trigger event, whether it was a button press, or a time of day, or a switch, or a motion sensor activate, or whatever.
If all you want is to have a list of lights come on at the same time, then you don’t need a scene.
If all you want is to have some lights turn on and some lights turn off From the same trigger event, then you don’t need a scene
But if you want to have two different devices turn on at two different dim levels, or two different colors, right now you can’t do that just with smartlighting or a routine, Because those will set all the devices to the same value. In order to have one light at 25% and another light at 50%, You either have to have two automations or use a SmartThings scene.
People have been asking for scenes for several years in smartthings, mostly just because it makes it easier to write multiple automations that create the same end result but have different initiating triggers.
Smartthings only introduced them about a month ago.
But Smartthings is a certified Z wave controller, and Z wave has both scenes and central scenes. Zigbee has scenes. The Hue bridge has scenes. And all of these have some subtle but important differences.
However, I don’t want to drag this thread too far off track. So I will just say that if you want to use double tap with the device in this thread to trigger a scene, it would depend on the double tap counting as a “button” and then you can do it with a single routine or a SmartLights automation. Or probably webcore. 
https://support.smartthings.com/hc/en-us/articles/115004258063-Scenes#Trigger_Scene