Understanding climate component (or how does a HVAC unit react)

I’m currently programming a HVAC unit in micropython that is basically a sonoff th10 switch connecting a simple actuator to my heating unit and has a temperature sensor connected.

However I’m lacking the understanding of a few configuration options the Climate component provides. Maybe someone can help me out here and explain how the typical HVAC unit deals with those options so my integration behaves in the same way:

  1. temperature_command_topic
    There is an option for a temperature command/state/template option that is used for setting the target temperature. However if I use the temperature_low_command_topic and temperature_high_command_topic options, the temperature_command_topic seems to be completely irrelevant in the frontend as well as in my HVAC implementation. Is that correct?

  2. away_mode
    What happens if I activate the away mode? I guess the hvac unit then uses another set of temperature_low and temperature_high?

Thanks for the help.