Modes are an essential part of the true home automation experience. With modes, you can set your devices to behave differently during each mode. For example you probably don't want your bathroom lights coming on at full blast in the middle of the night like you might at other modes.
In order to start using modes in your automations, you need to first create them in the Location section. Your Hubitat Elevation™ comes with four default modes, but you can change them in the Location section as well.
It's important to note that modes do nothing on their own. There are no built-in mode "settings"; modes will not change on their own. To set your modes, use Mode Manager, Rule Machine, or a similar app. There you can set modes to automatically change based on time of day, day of the week, presence and more. You can also program modes to change at the press of a button.
Once your modes are set you can use modes to change the behavior of your devices, creating rules that have device doing one thing in Day mode and a completely different thing (or nothing at all) during Away mode.