How to install third party apps on android (apps out of Google play store)

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Select this menu. Go to "Settings" and go to this "Lock screen and security" and you can see there is an option here "Unknown sources" which is right now disabled. So, enable it and select "OK". So, when you do this one then third party applications will be installed in your android device. So, this is how you can install third party application in your android device.