Hey @BigB! The Alarm features 3 modes in which 2 are considered armed. Of course, Disarmed mode is exactly that, disarmed. The Home and Away modes are considered armed modes. In Home mode, your perimeter or entry placed sensors are monitored and, in most cases, your motion detectors throughout the home are not. Check out our help center article which breaks down each mode.
There are also mode settings in the Ring app that will allow you to choose which sensors and motion detectors are included in which modes. I hope this helps!