Computer hardware is the physical components that make up a computer. They include devices that provide input or output functions and those that control the internal computer operations.
The main internal hardware includes the motherboard, central processing unit (CPU) and random access memory (RAM). The CPU plugs into a socket on the motherboard; the RAM modules fit into corresponding ram slots.
Motherboard
The motherboard is the centralized hub that connects the other components that make up your computer. It houses the CPU socket, into which the processor sits, allowing it to process instructions and communicate with other hardware elements like memory and expansion slots.
The motherboard also contains a chipset that facilitates communication between the CPU and other expansion cards, such as graphics and network cards. It may have slots for dual in-line memory modules (DIMM) and peripheral devices, such as Serial Advanced Technology Attachment (SATA), USB and newer Thunderbolt connections for high-speed data transfer.
CPU
The CPU is the heart of your computer, responsible for carrying out the instructions that make it work. It performs arithmetic and logical operations, moves data between memory and registers, and handles input and output.
A clock signal is used to synchronize the CPU’s operations. It provides the necessary timing to determine how long it takes to execute each instruction.
The CPU has all-purpose registers that hold operational data, and instruction registers that contain the binary numbers for each instruction it receives. It also has an arithmetic logic unit that performs basic math and Boolean logic operations.
RAM
RAM is a type of short-term memory that stores data your computer needs immediately. Your CPU and other components use this information to open files, run apps and games, and more. Then, when the system is finished actively working with that data, it pulls it back into storage for long-term storage.
RAM can come in the form of a soldered-on board that can’t be removed or removable modules called DIMMs. They slot into a special connector (memory bank) on the motherboard. Many newer modules are notched at one end so that you can’t insert them in the wrong direction.
Graphics Card
Graphics card is a special piece of hardware that is responsible for the rendering of computer graphics. It connects to the monitor using various ports and provides the frame rate, resolution and other important features.
The GPU performs complex mathematical calculations in order to render 3D computer graphics. It is also used for other purposes, such as computational photography and video processing.
Some graphics cards come in the form of a printed circuit board that is to be inserted into an expansion slot, while others have their own enclosures and are connected to the motherboard through a cable or docking station. Many modern computers and laptops include an integrated GPU.
Sound Card
Many home computers of the 1980s had motherboard-integrated sound devices, such as the Commodore 64, Amiga, PC-88, Sharp X1, Commodore Plus/4, MSX, ZX Spectrum and Archimedes. Workstations from Sun, Silicon Graphics and NeXT have their own integrated sound devices as well.
Most modern low-cost integrated (built into the motherboard) and expansion sound cards use audio codec chips that meet the AC’97 standard. These chips do not require any special hardware or drivers and provide a single mono or stereo output channel.
Early IBM PC-compatible sound cards like the AdLib card used a custom 3-voice FM synthesis chip to enable digital music composition and speech synthesis. It was eventually outsold by Creative Labs’ Sound Blaster which provided much better polyphony and also a MIDI interface for external MIDI instruments.
Network Card
A network card, also known as a network interface card or NIC, connects your computer to a computer network. It encapsulates data as frames that include frame headers and frame trailers and sends it over the network transmission media—copper wire or optical fiber for wired networks, electromagnetic waves for wireless networks. NICs are commonly installed inside desktop PCs, but smaller Personal Computer Memory Card International Association Ethernet cards that resemble credit cards are available for laptop and mobile computers.
NICs communicate at layers 1 and 2 of the Open System Interconnection networking referencing model. They allow your computer to connect to a router or network switch with an ethernet cable, which can be plugged into other devices within the same network such as printers and security cameras.
Disk Drive
The hard drive stores and retrieves large amounts of data for the computer. Current HDDs connect to the system over a digital data cable (40-pin IDE/ATA or 80-conductor PATA).
The firmware on the PCB sends commands to the actuator arm that reads the platters. It uses generous gaps and servo feedback to ensure all sectors are read accurately.
As HDD technology improved, form factors shrunk to 3.5-inch for desktops and 2.5-inch for laptops. The latest drives use HAMR or other advanced technologies that enable higher capacity and more stable disks.