Computer hardware is the physical parts of a computing system that control input and output functions. Internal components include the motherboard, central processing unit (CPU), random access memory (RAM) and data storage devices.
RAM stores data that the CPU uses for quick execution, and it is volatile, meaning the contents are lost when power is removed. All computers require some form of non-volatile storage for permanent data.
Motherboard
Motherboards are the backbone of the PC, providing the central communications point to which all other components and external devices connect. A motherboard contains the computer’s central processor, memory and many expansion slots for add-on hardware.
The CPU slot is a socket that holds the microprocessor, which converts electrical signals into the computer’s programming language (1 and 0). A fan and heat sink keep the microprocessor cool. Other expansion slots provide connectivity ports such as USB, SATA and PCI. Other features include a debug LED and M.2 slots for solid-state drives (SSDs). Motherboards are available in various sizes, including mini-ITX that allows for ultra-compact form factors while sacrificing some expandability.
Processor
A computer’s processor, or CPU, carries out instructions from software applications to perform tasks and calculations. It also processes data for output, such as video images or text on the screen. The hardware components that handle these functions are referred to as processing devices, and include the CPU, GPU, and motherboard.
The CPU consists of several functional units, such as the control unit and arithmetic logic unit, which perform math operations (addition, subtraction, multiplication, and division) and logical operations (AND, OR, and NOT). It also contains memory registers, which hold instruction and data signals, and an internal bus that handles communication with main memory and high-speed input/output devices.
RAM
When you play a video game or stream a movie, the computer loads that data into RAM so the central processing unit can get to it quickly. The CPU uses that data to give you a smooth experience.
RAM is volatile, meaning it loses its data when the power is turned off. So it’s essential that your PC has plenty of RAM to work with.
The early standard for desktop RAM was SIMM, but today all desktop computers use DIMM slots (and many laptops too). Most of them have a type called DDR SDRAM that works in synchronization with the CPU, reducing wait times and boosting performance.
Hard Drive
A hard disk drive stores data magnetically on platters. Its actuator arm moves a read/write head across the surface of each platter, changing its magnetization to represent binary data bits (1s and 0s).
Modern HDDs use zone bit recording, which increases writing speed from inner to outer zones and allows more data per track. HDD capacity numbers exclude a number of sectors reserved for defect management and operating system usage.
Using write caching and frequent defragmentation can improve an HDD’s performance. These techniques rearrange saved data so that the most frequently used blocks are stored together, reducing the distance the read/write head needs to travel.
Graphics Card
Graphics cards, also called GPUs or graphics processor units, handle rendering images, videos and 3D graphics. They are the most sophisticated components in a PC and in some ways behave like stand-alone computers. The best modern graphics cards are capable of performing complex image processing tasks that previously could only be handled by the CPU. This includes ray tracing, resolution scaling and AI-assisted image stabilization.
The most popular graphics cards are designed by two rival brands, Nvidia and AMD. Despite their differences, they often offer similar performance and value. They are often installed in an expansion slot on the motherboard and can be upgraded as newer models become available.
Sound Card
Managing the flow of sound data between your computer and connected devices, sound cards are instrumental in ensuring proper input/output processing. They also bypass electrical interferences that often bleed into the built in sound processing portions of your motherboard.
Aside from converting digital signals into analog output for speakers and headphones, sound cards provide advanced audio processing, low-latency audio input/output and support various audio formats. They’re a must-have for gamers who want to enjoy better positional audio and high-fidelity music, as well as professionals who use their computers for content creation like podcasting and live streaming. They’re also commonly used in recording studios.