What does the 'Eco' button do in a Kia Sportage?

I heard about an 'Eco' button in the Kia Sportage, but I'm not sure what it does. Can someone explain its purpose?

The 'Eco' button is a fuel-saving feature. When activated, it adjusts the transmission, engine, and even air conditioning for maximum efficiency.

It's perfect for city driving, where you're constantly stopping and starting. It can improve your gas mileage up to 3%.

Make sure to turn off the 'Eco' button when towing or driving in hilly areas, as it can reduce power and make it harder to accelerate.