What Is Computer Hardware?

Computer hardware is the physical components inside your computer that make it run. It includes everything from the monitor to the keyboard and mouse.

The most important part of computer hardware is the microprocessor chip, which is called the central processing unit. The CPU is mounted on a motherboard in a special socket.


A motherboard acts as the “brain” of a computer, organizing and connecting all other components. Its most crucial function is enabling the central processing unit (CPU) to communicate with other critical hardware installed in expansion slots, such as the graphics card and RAM.

The motherboard also contains circuits that coordinate computer processes and a heat sink to absorb and redirect thermal energy during operation. It usually has several 3.5mm color-coded and labeled audio ports for connecting to speakers or home theater systems, as well as HDMI and other digital display connections. Often, a dedicated sound card installed in one of the expansion slots is preferable for high-quality audio.


The central processing unit, or CPU, is the heart of a computer. It controls all other components and communicates with input and output devices. It reads instructions from memory, interprets them and directs the work of other parts of the processor. The arithmetic logic unit performs integer arithmetic and bitwise logic operations on data words and control signals from the control unit.

The CPU fetches the program instruction from memory using an internal clock, then decodes it into sets of CPU configuration signals. The CPU then applies those signals to internal memory and other hardware devices. Ultimately, the result of the CPU’s calculations is displayed on the screen of the computer.


RAM is a type of internal storage that stores data quickly for the CPU to access. It differs from other types of storage, like hard disk drives and solid-state drives, which are non-volatile and retain data even when power is cut.

When you do computing-intensive tasks like typing, saving a document or playing a video game, all of that work is executed in your computer’s RAM. The more RAM you have, the faster these operations will be.

Graphics Card

A graphics card converts the numbers in a spreadsheet, words in a document and images on a web page into something that can be displayed on your monitor. It also handles the pixels that make up a video game, with higher frame rates (fps) translating to a more realistic experience.

It consists of a graphical processing unit, or GPU; memory chips that store display data; and a digital-to-analog converter. You can check the specifications of your card by opening the System information app and selecting Display information. The best cards are designed to fit comfortably inside your PC case and to look the part, with many featuring decorative fans and heat sinks.

Sound Card

Sound cards let you connect headphones, speakers and microphones to your computer. They can also help you set up surround sound, MIDI and other features.

Most sound cards convert digital code into analog waves that can travel through air to your speakers. Some even use their own processing power to lessen the CPU load.

Dedicated sound cards used to be expansion boards, often with ISA or PCI slots, but as motherboards became more advanced they integrated basic sound card functionality into their chipsets. Today, low-cost integrated audio codecs that meet AC’97 standards are commonly found in modern motherboards. This makes it unlikely that you’ll need to buy an external sound card unless you’re building a very old computer.

Network Card

A network card (also called a network interface card or NIC) is an expansion card that connects your computer to a wired or wireless data network. It prepares and sends data on the network, and it also controls the flow of information.

A NIC transmits electrical impulses from your computer as it sends requests to a web server on the Internet, and it receives the data that web servers display for users. It operates at the OSI networking referencing model’s physical layer and data link layers.

A NIC requires a data bus architecture compatible with the computer, and it needs a socket for the type of cable that’s used in the network. Today, most computers come with integrated NICs built into the motherboards.