Recovery, in Android, refers to the bootable partition, in which the recovery console is installed.
It contains tools to help repair your installations as well as install official OS updates by using a combination of key presses or instructions from a command line sometimes.
Android is open, meaning the recovery source code is available, so that building a customized ROM is relatively easy.
1. To start you will need your phone switched OFF, so please do that, and hold down power button.
2. Now press combination of Volume down button with power button together.
3. Now just wait for a LG logo and let go of the buttons.
4. And this is it! after few seconds your phone will end up in recovery mode.
5. To navigate here you have to use your volume buttons and to select use power button.