Computer Hardware

Computer hardware comprises all the physical, tangible components that make up a computer. These include the case and its contents such as the motherboard, processor, memory, storage, and power supply, as well as external devices such as the keyboard, mouse, and monitor.

Hardware differs from software, which consists of written instructions that have no physical form. The two are interdependent: hardware cannot perform tasks without running software, and software cannot run without hardware. The integration of the two is called the system architecture.

Major Components

The central processing unit (CPU) executes instructions and performs calculations and logical operations. Random-access memory (RAM) temporarily holds data and running programs; this data is lost when power is cut. The motherboard connects all components and routes data and power. The power supply converts external electricity and distributes it to the components.

Storage and External Devices

Persistent storage retains data even when power is off. Common types include the hard disk drive (HDD) and solid-state drive (SSD), which is faster and has no moving parts. Input devices (keyboard, mouse, camera, microphone) feed data in; output devices (monitor, printer, speaker) display results. The graphics processing unit (GPU) specializes in image computation and increasingly handles machine learning tasks.

System Types

Hardware varies in scale and purpose: desktop computers, laptops, modern smartphones, data center servers, and small embedded processors in automobiles, medical equipment, and home appliances. All these systems share the same basic architecture: input, processing, memory, storage, and output.

Evolution and Environmental Impact

Since the invention of the transistor and integrated circuits, the number of transistors on a chip has grown steadily, lowering cost and increasing power. Meanwhile, discarded electronics create e-waste containing hazardous materials; many countries have established regulations on recycling.