With away mode, your air conditioner or heat pump will only switch on to maintain conditions to fall within the target that you've set, and once it's been maintained (see switch off targets), it'll automatically switch off.
If you have a condition that you'd like maintained at certain times when you're away, you can now do so with Away mode where the AI will automatically monitor and switch on/off as necessary. This reduces your system run time which could make a big difference especially if you worry about your pets at home in a hot summer day or if you have valuables that are sensitive to humidity changes.
Since the AI is closely monitoring and maintaining the in-room conditions (temperature/humidity), it minimizes the gap of which your AC needs to cool/dry/heat to maintain comfortable conditions. This means the compressor won't have to run at full capacity each time it comes on, hence consuming less energy.