The Most Important PC Hardware Components

A computer’s central processing unit (CPU) processes and executes digital instructions sent by programs. Its clock speed determines its performance and efficiency.

Random access memory — or RAM — stores code and data the CPU is currently using. RAM is volatile, and the contents disappear when the power is turned off.


The motherboard is the flat piece of circuit board that holds most of the computer’s core components. The most important parts of the motherboard are the CPU socket (for Intel processors) and RAM slots, both of which allow the CPU to communicate with other chips in your computer, including memory and expansion cards, using a series of circuits called buses.

The chipset, which is located on the motherboard, acts as a hub that connects these other busses. It receives data from the power supply and transmits it to the CPU, RAM, PCIe and other expansion cards. It also takes input from the BIOS, which performs hardware initialization during startup and provides runtime services for OS and programs.

The motherboard also contains expansion ports, like USB and Gigabit Ethernet. It may also feature several PCIe x16 slots to support multiple graphics cards, which can improve performance in graphical computing tasks. It will also contain a voltage regulator module, which regulates voltage and current to prevent hardware damage from excess currents.


The CPU is the brain of your computer, guiding all data processing much like a human guides its body. It sends information to other components of the system for processing and saves final processed data results before sending them out as output. It also stores instructions in its internal memory unit, aka main memory or primary storage, also known as RAM (Random Access Memory). This type of memory is volatile and erases itself when the power shuts off.

The two major parts of the CPU are the Arithmetic Logic Unit (ALU) and the Control Unit. The ALU handles arithmetic and logical operations, while the Control Unit deciphers and carries out instructions. Different CPUs have different types of instruction sets, and software written for one will not run on others.

Most modern processors are multi-core and use multiple physical cores inside the main chip. This allows them to carry out many tasks simultaneously. These are popular with gamers and content creators that use demanding programs.


RAM, which stands for Random Access Memory, is the short-term working scratchpad that your computer uses to store code and data that are being used. It keeps the data on-hand so the CPU can read it instantly. Compared to older storage media that reads data in a fixed sequence, this makes RAM significantly faster.

Most computers come with at least two RAM modules, which are also known as DIMMs, that plug into the motherboard. The chips on these modules can be accessed individually and are sold separately, so that you can upgrade your PC’s RAM with more powerful options. Most desktops use DIMMs that are packaged into matching pairs or “banks” on the motherboard to maximize performance, while newer laptops and mini PCs generally use a smaller version of the DIMM called a SO-DIMM (small outline dual inline memory module).

Video Card

The video card sends graphical information to the computer monitor. It’s also known as a graphics card, graphic adapter, or video controller and installs in an expansion slot on the motherboard. The most common type is a NVIDIA or AMD GPU-based video card that uses an HDMI, DVI, or VGA port for connection to the monitor.

A video card has memory chips that store data and instructions for quick access by the processor core. It also has a cooling system to prevent the components from overheating after extended use.

Many modern video cards have multiple GPUs (Graphics Processing Units). This allows the card to perform complex graphics calculations much faster than a single CPU could do alone. It can also allow multiple monitors to be used simultaneously. This is great for graphics-heavy programs such as games and design tools. Some manufacturers, such as Nvidia and AMD, even offer technologies that allow two identical cards to be linked together in the same system for even more power-efficient performance.