Which component checks the computer's hardware during the startup sequence?

The component that checks the computer's hardware during the startup sequence is known as POST, which stands for Power-On Self-Test. When a computer is powered on, POST is the first process that runs. It performs a series of diagnostic tests to ensure that the essential hardware components, such as the CPU, RAM, keyboard, and other critical parts, are functioning correctly. If POST encounters any issues, it typically generates error codes or beep patterns to signify hardware malfunctions, allowing the user or technician to address any problems before the operating system is loaded.

While BIOS is a firmware interface that initiates this process and contains the code that carries out the POST, it is specifically the POST itself that conducts the hardware checks. This is a crucial step in the boot sequence, and if everything checks out, the BIOS then hands control over to the bootloader to begin loading the operating system. Thus, understanding the distinction between POST and BIOS helps clarify their respective roles in the startup sequence.