Resetting an Apple TV will erase all of its content and settings, and return the device to its original factory settings. This can be useful if you're experiencing persistent problems with the device. To reset an Apple TV, you'll need to go to the "Settings" app, then "System" and select "Reset". From there, you'll have the option to reset the device to its factory settings. Before resetting, make sure to back up any important data as this process will erase all of your content and settings.