Home vs Away are location.modes. You get to set them whenever you want to based on whatever you want.
The following FAQ should help explain. The examples are from the classic app, but the concepts are the same.
“Routines” are a name for a particular kind of automation that was available in the classic app.
SHM is the security feature in the classic app. STHM is the equivalent in the new V3 app.
FAQ: Armed/Disarmed states vs Away/Home modes confusion (Classic app)