What Does the 'Efficiency' Mode in My Audi A2 Do?

I recently purchased a used Audi A2 and noticed it has an 'efficiency' mode button. What exactly does this mode do and is it worth using?

The 'efficiency' mode in Audi A2 adjusts the vehicle's performance to reduce fuel consumption and emissions. It does this by optimizing the engine's power output and limiting certain functions such as air conditioning. It can definitely be worth using, especially for longer trips or city driving with frequent stops and starts.