What are the different system settings available on my Honeywell thermostat?

Press the SYSTEM button to select from: Heat (controls only the heating system), Cool (controls only the cooling system), Off (heating and cooling systems are off), Auto (thermostat automatically selects heating or cooling based on indoor temperature), or Em Heat (for heat pumps with auxiliary heat; compressor is locked out). Note that Auto and Em Heat settings may not appear depending on installation.