BIOS (basic input/output system) is the program a personal computer's microprocessor uses to get the computer system started after you turn it on. It also manages data flow between the computer's operating system and attached devices such as the hard disk, video adapter, keyboard, mouse and printer.


Read-only memory (ROM) is a type of storage medium that permanently stores data on personal computers (PCs) and other electronic devices. It contains the programming needed to start a PC, which is essential for boot-up; it performs major input/output tasks and holds programs or software instructions.

CMOS is an onboard, battery powered semiconductor chip inside computers that stores information. This information ranges from the system time and date to system hardware settings for your computer.


When power is turned on, POST (Power-On Self-Test) is the diagnostic testing sequence that a computer's basic input/output system (or "starting program") runs to determine if the computer keyboard, random access memory, disk drives, and other hardware are working correctly.
A bootstrap is the program that initializes the operating system (OS) during startup. It referred to a bootstrap load button that was used to initiate a hardwired bootstrap program, or smaller program that executed a larger program such as the OS.
The kernel is the most fundamental part of an operating system. It can be thought of as the program which controls all other programs on the computer. When the computer starts, it goes through some booting functions, such as checking memory. It is responsible for assigning and assigning memory space which allows software to run.
The kernel provides services so programs can request the use of the network card, the disk or other pieces of hardware. The kernel forwards the request to special programs called device drivers which control the hardware. It also manages the file system and sets interrupts for the CPU to enable multitasking. Many kernels are also responsible for ensuring that faulty programs do not interfere with the operation of others by denying access to memory that has not been allocated to them and restricting the amount of CPU time they can consume.
We have to set up CMOS through BIOS setup program, and BIOS information is stored in CMOS. So at most of time, we usually called CMOS setting as BIOS setting. Both of them are settings on computer hard ware. And setting parameters are saved in CMOS chip.