Bare metal programming is a low-level type of programming that is hardcoded to a system at the hardware level and operates without an abstraction layer or operating system (OS). It also interlinks with the hardware, considering the specific build of components.
The term bare metal means a computer with no operating system, no partitions, and no installed software applications. It is the bare hardware and disk. In some instances, it may contain the basic input/output system (BIOS).