Sometimes you might need to reboot (or restart) a strange Android device to fix issues like app freezes/crashes and slow performance. The details may vary, but these reboot instructions generally apply regardless of your phone’s manufacturer or Android version.
How to Reliably Reboot Android Phones and Tablets
Press and hold the power button for a few seconds. This is usually located on the right side of the device.
A menu will appear with the option Power off. The latest Android version may offer other options, including Reboot, which is a better option.
Some devices work a little differently. For example, the latest Pixel phones display the power off menu when you press the Power + Volume Up keys at the same time.