The Basics of Computer Hardware

pc hardware

Computer hardware consists of all the physical components inside a computer that make it work. It includes the case, central processing unit (CPU), random access memory, hard drive, monitor and mouse.

The CPU is the heart of your computer. Its size and speed determine what tasks the computer can do.


A motherboard is the central circuit board that connects all of the other components of a computer. It houses the CPU, memory, hard drive and various ports and expansion slots. It’s also the hub for connecting external devices like a monitor, keyboard and mouse.

Modern motherboards typically feature PCIe slots for adding peripherical expansion cards that increase a computer’s capabilities, including graphics cards, solid-state drives and network adapters. These slots use low-latency data lanes that transmit information at the same time, compared to the parallel transfer used by older IDE devices. Motherboards also include a BIOS (or UEFI in modern systems) that initializes hardware during the startup process and hands control to the operating system.


The computer’s memory is where it keeps all the information it’s working on, allowing it to access it quickly. This is why opening a new app or webpage takes almost no time at all.

RAM consists of capacitors and transistors, which store an electric charge that corresponds to data bits. These are constantly being filled and refilled with electricity, which allows them to process data at lightning-fast speeds.

The RAM in a PC typically comes on rectangular flat circuit boards called memory modules. A modern computer with a Windows operating system needs at least 8GB of RAM, while anyone who wants to play high-end games should have 16GB or more.

Hard Drive

Computer hard drives are the semi-permanent storage devices that hold all your data, programs and personal files. They consist of spinning platters that store digital information read by fast-moving read/write heads.

Each tiny portion of the platter holds a one or a zero, and the read/write head can input either of these by changing the magnetism of specific portions.

Internal hard disk drives usually reside in a drive bay and connect to the motherboard via an ATA, SATA or SAS connector. They are non-volatile, so they retain data even when the computer is turned off. Internal HDDs have capacities of up to 20 TB.

Video Card

A video card is an expansion card that connects to the motherboard of a computer to create a picture on the display. Also known as a graphics card, video adapter or display controller, it performs a number of tasks that normally are handled by the CPU (central processing unit).

Unlike early cards that simply forwarded output from the processor to the screen, modern video cards are more like co-processors. Some can even process physics calculations to speed up 3D rendering.

The type of card you need depends on what you use your computer for. For example, gamers need high-end cards that provide extra processing power and video memory to improve performance.

Sound Card

Unless your laptop or contemporary computer monitor has built-in speakers, you need a sound card to get good audio out of your system. Dedicated sound cards provide better quality than integrated motherboard audio and often include additional input/output ports for things like microphones, headsets, and speakers.

Historically, computer audio quality was notoriously subpar. Component-produced noise, uninsulated circuitry, and proximity to other noisy parts of the motherboard were all responsible for this. A dedicated sound card solves this by shielding internal components and separating them from the noisiest parts of your PC.

From the beeps and boops of early personal computers to full orchestral soundtracks in modern gaming, a sound card makes the difference.

Network Card

The network card, also known as a network interface controller or NIC, allows your computer to communicate over a local area network (LAN) or wide area network. The NIC connects your computer to other computers, printers, or other devices that can be accessed over the Internet.

Previously, a NIC was an expansion card that plugged into slots on your motherboard, but now most pre-made desktops and laptops have a built-in Ethernet port. External NICs are available for older machines that require them and connect via USB. An internal NIC uses one of the standard motherboard slot formats like Peripheral Component Interconnect, PCI-Express, or Industry Standard Architecture.