Computer hardware refers to all the tangible components inside a desktop computer. This includes the monitor, computer tower (motherboard, CPU, graphical processing unit of some sort, RAM and storage device) and input devices like a keyboard and mouse.
This picture shows a flat “motherboard”, about as thick as an 8.5 x 11 piece of paper. The fingernail-sized CPU is held tightly by a lever mechanism and covered with a metal chip cover that conducts heat to its attached heatsink.
Motherboard
The motherboard is the central hub that connects a computer’s functional components so they can interact. It acts as a backbone on which modular parts like the CPU, RAM and storage devices can be installed. The motherboard also distributes power to each component and includes voltage regulators that ensure that the different components don’t get overloaded or experience power spikes.
The motherboard contains traces that lead to slots that house the CPU chip (Intel or AMD), as well as random access memory slots for system memory and expansion slots for additional memory cards, networking cards, sound and graphics cards. Modern motherboards often incorporate a tamper-resistant technology known as TPM 2.0 for cybersecurity protection.
CPU
The CPU is the main processor that executes all of your computer’s logical and mathematical calculations, making it possible to use programs like your email program or web browser. It is made up of billions of microscopic transistors arranged on a single computer chip. These transistors act as tiny switches, sending and receiving the binary ones and zeroes that underlie all of your computer’s operations.
These transistors have been progressively getting smaller over time, allowing the CPU to perform faster. This is known as Moore’s law. Today, most computer chips are based on the x86 or ARM instruction set architecture (ISA). The CPU has one job: to process instructions it receives from memory.
Memory
A computer uses different kinds of memory and storage to store files permanently or temporarily. The most important of these is the primary memory known as RAM (random access memory). This holds important currently-used data and codes on standby so they’re available for rapid loading when programs are opened. It is volatile, which means the information stored in it will be erased when you turn off your computer.
Most PCs have RAM packaged as chips on a small card called a DIMM that plugs into the motherboard. Today, these are usually DDR4 modules that can transfer data twice as fast as the earlier versions.
Graphics Card
The graphics card (also called the video card) sends image information from the CPU to a monitor or other display device. High-end cards use dedicated processors to handle intensive tasks like 4K video editing and gaming at 60 frames per second or more.
Modern GPUs use multiple processors, which are called cores or streams. The more cores, the better the card performs. They also have a clock speed, which determines how many calculations they can do per second.
The GPU can connect to the monitor via a variety of ports including VGA, HDMI, and DisplayPort. Some cards can even support two or more monitors with a technology called Crossfire or SLI.
Hard Drives
The hard drive is the computer hardware that stores digital data on a long-term basis. It serves as the main and largest storage device for operating systems, programs and file data files such as images, music or videos.
Hard drives have disc-like objects called platters that are divided into sectors. Each sector can accept an electrical charge, and the actuator arm holds read/write heads that can record or access these charges.
Each time a program needs to access data from the hard drive, it takes a little of this data from each sector. This adds up and can slow down program function. Fortunately, newer solid state drives (SSDs) are reducing this problem.
Other Components
The central processing unit (CPU), known as a microprocessor, is the heart of your computer. It controls all the inputs and outputs, processes data, and stores information for you to access.
The system clock generates electric pulses that send signals to other parts of the computer. The faster the CPU’s clock, the more work it can do in a second.
Cache memory is special high-speed memory that stores instructions and data the CPU uses frequently to speed up processing. The motherboard has sockets for expansion cards such as sound and graphics.
Other computer hardware includes USB ports, ethernet ports, and firewire ports. A hard disk drive and solid-state drive are storage devices that are non-volatile, meaning they retain their data even when the computer is turned off.