There are different ways to reset your Android device, depending on what you want to achieve. If you want to erase all your data and settings and restore your device to its factory state, you can do a factory reset. If you want to restart your device when it’s not responding, you can do a hard reboot.
To do a factory reset, go to Settings > Backup & Reset > Factory Data Reset. This will delete everything on your device, so make sure you back up your data first. You may also need to enter your Google account password after the reset.
To do a hard reboot, press and hold the power button for at least 20-30 seconds until the device powers off. This will not delete any data or settings, but it may help fix some issues or glitches.