There are different modes in AC and a lot depends on the manufacturer on how many modes are added into the model. Some of the known modes in AC are as follows -
1. Fan mode
2. Split AC mode
3. Cool mode
4. Sleep mode
5. Power saving mode
6. Dry mode
In case of fan mode and dry mode, the AC avoids using the cooling agent. And this way only the room is dried with existing room air and temperature.
In case of split AC mode, the temperature is adjusted with the fan at first and maintained the cool. This is handy for offices and rooms where the outside air change may occur on regular basis and there is temperature fluctuations.
Power saving mode reduces energy drain to keep the room cool. And the temperature is maintained preserving the energy.
Sleep mode, maintains the room temperature cool and avoids affecting room temperature to be too cool or too hot, allowing the person to maintain the sleep.
Cool mode, should be used when the AC needs to be keeping the room temperature as much cool as possible.