Computer hardware

What is a computer? – Computer hardware

Conventionally, the central unit of a modern digital* computer* consists of at least one processing element, typically a central processing unit (CPU) in the form of a microprocessor, along with some type of computer memory. Both the CPU and the memory are typically made of semiconductor chips.
    In the processing element the arithmetic and logic unit (ALU) carries out arithmetic and logical operations,* and a sequencing and control unit (CU) reads and interprets the instructions* of the running program* sequentially. In some cases the CU can change the order of operations, e.g. in response to stored information.*
    Peripheral devices include input devices (keyboards, mice, joysticks, microphones, cameras etc.), output devices (monitors, printers, loudspeakers, projectors etc.), and input/output devices that perform both functions (e.g. the 2000s-era touchscreens).
    Storage units (e.g. HDDs or SSDs, optical drives and discs like CDs or DVDs, USB flash drives etc.) and network* adapters can also be considered as input/output devices. Such peripheral devices allow information to be retrieved from internal or external sources, and they enable the results of operations to be saved and retrieved again for further processing.*

Computer hardware* is the physical portion (i.e. the technically implemented units) of a digital computer. Some of the main hardware units of a desktop computer are as follows:

The computer can operate automatically, that is, it is capable of executing the currently running program by itself, without any human intervention. At hardware level, the basis for the automatic operation is provided by the instruction cycle executed by the control unit through endless repetitions.

Boda István, 2023.