BOOTLOADER A boot loader, also called a boot manager, is a small program that places the operating system (OS) of a computer into memory . When a computer is powered-up or restarted, the basic input/output system ( BIOS ) performs some initial tests, and then transfers control to the Master Boot Record (MBR) where the boot loader resides. Most new computers are shipped with boot loaders for some version of Microsoft Windows or the Mac OS. If a computer is to be used with Linux , a special boot loader must be installed. In Simple Words Press PowerButton Phone BootsUp ! The Screen you see is knows as Splash Screen or Boot Screen. In background a Process is going on which Checks - Your OS Files are Safe Your OS Files are not Corrupted Any Securit...