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 get to Recovery mode remember your phone has to be turned off. Press and hold Power Button if it isn't.
2. Next thing you willl have to do is to press Volume UP and Power Buttons combined for about 5 seconds.
3. Now let go off the power button and keep holding on volume key.
4. After that you will reach Recovery mode, congratulations.
5. Navigation buttons here are Volume Keys and for confirmation you have to use Power Button.