Computer hardware includes all the physical parts that contribute to a computer’s overall performance. It includes processing devices like central processors and random access memory, storage devices such as hard disk drives or solid state drives, and graphics cards that help render images and video.
The flat motherboard, about the size of a 8.5 x 11 piece of paper, houses the CPU and RAM. It has a metal chip cover that helps conduct heat to its (not shown) copper heat sink.
Motherboard
Motherboards, also known as main boards or system boards, are the flat pieces into which most of your other components plug. They are essentially the central nervous system of your computer.
The ATX standard (pictured here) and its derivatives—including the smaller microATX, mATX, E-ATX, and mini-ITX standards—are the most popular in desktop PCs. They feature 305*244 mm dimensions that offer ample room for expansion slots and ports.
Many motherboards offer multiple x16 slots for two graphics cards to work in parallel, increasing performance in graphics-intensive applications. Most motherboards include a cooling fan to help prevent the components from overheating.
CPU
The CPU (central processing unit) is the electronic machinery that executes programs so you can call your friends, play games, and write documents. You can find a CPU in all modern computers, including tablets and smartphones.
A processor has a set of instructions that it follows, much like the brain of a human body. The speed at which the CPU completes instructions is known as its clock rate.
Modern CPUs can also act like multiple physical cores to improve performance. This is called hyper-threading. For example, a quad-core CPU can appear to function like two physical cores for faster execution times.
RAM
RAM temporarily stores all the data your computer processor needs to complete tasks like launching a web browser or editing a document. More RAM means the computer can work faster and more smoothly.
RAM is stored in microchips that are grouped into memory modules and plug into slots on the motherboard. Each memory cell consists of two electronic components: a capacitor that can be filled with electrons to store a “one” and a transistor that can switch the capacitor on or off.
The older type of DRAM uses a capacitor that needs to be refreshed with comparatively large bursts of power every millisecond, which consumes a lot of energy. Modern computers use an upgraded version of DRAM known as SDRAM (synchronous dynamic random access memory).
Hard Drives
Hard drives (also known as disks) are non-volatile storage that retains data when the computer is turned off. They store files and programs that are too large for RAM.
HDDs have disc-like objects called platters, which hold thousands of subdivisions that each can accept an electric charge. The actuator arm reads the charged areas and converts them to binary data, 1s or 0s.
A DSP in the drive electronics decodes the analog signals and presents a standard interface to the rest of the computer. Current drives connect to the motherboard via a single data/control cable, replacing older interfaces that used separate cables for both data and drive control.
Graphics Card
A graphics card, or GPU (Graphics Processing Unit), is a specialized chip that handles the rendering and display of images on your computer screen. It offloads demanding graphics processing from the main processor, improving gaming performance and graphical realism.
Graphics cards can be integrated into the motherboard or standalone. Integrated chips are good for basic computing and light gaming but can struggle with 3D or high-stress programs.
Discrete GPUs, on the other hand, come in different sizes based on the number of PCIe lanes they support and offer higher data throughput. NVIDIA’s GeForce cards are popular for gamers and offer features like anti-aliasing and ray tracing.
Sound Card
A sound card enables the computer to send audio signals to speakers and headphones. It is sometimes integrated into the motherboard as an internal expansion card but it can also be found in external devices such as USB sound adapters.
Basically, the sound card turns digital bits (1’s and 0’s) into an analog signal which is then transmitted to speakers. It can also record a source that is playing. Sound cards can offer a wide range of features from basic volume controls to virtual surround and positional audio for the best gaming experiences.
Power Supply
A power supply is a plastic or metal box that takes Mains (AC) input at one end and steps the voltage up or down to a DC output at the other. It can also control current, ensuring that the component draws exactly the right amount of power.
Older computers[when?] designed for 5 V operating voltage required a +5 V rail and a -12 V rail for disk drive motors and serial ports. The ATX 1.0 standard added a four-pin P4 connector to the motherboard to support higher-power microprocessors that operate on +12 V.