Bare metal is a computer system without a base operating system (OS) or installed applications. It is a computer's hardware assembly, structure and components that is installed with either the firmware or basic input/output system (BIOS) software utility or no software at all.
Bare metal is a term used in enterprise computing environments to distinguish standard and barebone computers. Typically, a computer shipped from a manufacturer is in a bare metal state and though installed software is not included, the computer contains essential hardware components, such as processors, motherboards, hard disks and network cards. A user accesses the mounted firmware/BIOS to operate the computer and install a preferred operating system (OS). If the firmware or BIOS utility are not available, they are installed with external storage sources, such as serial, parallel, Universal Serial Bus (USB) and optical storage devices.