Your tado° can be either in Home or Away Mode.
Your tado° is in Home Mode when your smartphone is detected to be at home or when you have turned off Location-based Control for a time block. When you let tado° determine your optimized Away Temperature, it makes sure your home is already at the right temperature when you get there by preheating or precooling your home when you approach your home.
While no one is at home you may want to reduce the temperature in your house to save energy. tado° does this for you by detecting when the last person leaves the house and activating the Away Mode. You can either leave it up to tado° to determine the ideal Away Temperature or set a certain temperature for the time when you are not at home.