How does keep me cozy 2 work

Every number I enter into heating and cooling settings changes thermostat set-points to 70/73. Is settings where I input set points. I have read all the threads one was saying its for a offset of the thermostat. Not sure.
If someone has the time can you explain it to me thanks

You might refer to the code of the smartapp at: https://github.com/SmartThingsCommunity/SmartThingsPublic/tree/master/smartapps/smartthings/keep-me-cozy-ii.src