Many home treadmills consist of adjustable incline settings

https://home-treadmillsjshs091.moderncairn.com/posts/why-do-so-many-people-want-to-know-about-home-running-machine

Lots of home treadmills consist of adjustable incline settings, allowing you to imitate outdoor surface for stronger legs and much better workout variety, whether you're training for hills or burning more calories.