The Basics of Computer Hardware

pc hardware

Computer hardware is the physical parts of a computer. It includes the central processing unit, random access memory, monitor, keyboard and mouse. It also includes expansion cards for graphics, sound and networking.

Persistent storage stores bytes on hard drives that use spinning magnetic patterns or flash chips. It keeps data even when the power is off.


The motherboard is the central backbone on which other modular parts like the CPU, RAM and hard disk are installed. It also acts as the transportation hub where various expansion slots are available to install other devices and interfaces.

It has a power connector plug that connects to the computer’s primary power supply and distributes electricity optimally. It also coordinates the various devices in the computer and maintains an interface among them.

Motherboards have ports for connecting external devices such as monitors, keyboards, speakers and USB peripherals. They also come in different sizes called form factors. Generally, larger motherboards have more expansion slots to allow for upgrading the computer’s components.


The processor, or CPU, is the heart of any computer. It interprets the instructions that the operating system sends it and performs trillions of calculations. It also manages input and output, making it one of the most critical components of any PC.

The four primary functions of the processor are fetching, decoding, executing, and writing back instructions. It also includes an Arithmetic Logic Unit, which performs arithmetic and logic operations; a Floating Point Unit, which manipulates numbers more quickly than basic microprocessor circuitry can; and L1 and L2 cache memory, which stores data locally to save time retrieving it from RAM.

The CPU is part of a larger integrated circuit called the chipset, which mediates communication between the processor and other components on a motherboard. This includes the North Bridge, which connects the processor to high speed components like main memory; and the South Bridge, which supports auxiliary interfaces and busses.


Often referred to as primary storage, memory holds instructions and data temporarily before and after they are processed by the CPU. It is volatile, meaning it loses information when the computer is turned off.

In addition to regular RAM, some computers have a cache built into the processor which improves performance by reducing the amount of data that has to be transferred in and out of standard memory. A cache’s size is typically measured in KB (kilobyte).

All desktop PCs use a form of memory called DDR SDRAM — a development of dynamic RAM that allows data transfers to occur in synchronization with the CPU’s clock cycle, which improves performance.

Graphics Card

The graphics card takes digital data and translates it into pixels that the monitor can display. That data can include the numbers in a spreadsheet, words and images on a website, or video frames that make up TV shows and movies.

To produce these pixels, the GPU must calculate many triangles or vertices per second. It must then rasterize them (fill in the straight lines) and add color, lighting, and texture.

The GPU also needs somewhere to store information about the pixels and completed images. This is called video RAM or VRAM. The fastest cards use GDDR memory, while cheaper ones may use system RAM.

Sound Card

The sound card, also called an audio card, is responsible for the quality of sound your computer produces through wired speakers or headphones. It translates digital audio signals into analog ones and vice versa. It is able to do this because it uses an analog-to-digital converter (ADC), which takes a series of measurements of the analog wave at fixed intervals and reconstructed them as digital data.

A sound card also has input and output jacks for connecting headphones, microphones and other devices. Advanced sound cards may offer more ports like a digital optical out or a DB-15 connector for MIDI devices or game joysticks.

Network Card

Network cards connect a computer to other computers and devices on a local area network (LAN). They enable communication between the LAN using standard network protocols like Ethernet or token ring. They implement the first two layers of the OSI model, namely the physical layer and the data link layer.

Most modern NICs have additional features that allow for smooth and reliable networking. These include advanced traffic handling mechanisms that prevent lag during data-intensive activities.

The NIC also supports the MAC address, which distinguishes each device on the network. It is also designed to work with specific types of connectors for the ethernet cable.