Computer hardware refers to external and internal devices that enable the core functions of computing. From massive mainframe computers that fill entire rooms to the portable laptops used in business and at home, these devices perform essential calculations to make modern life easier and more efficient.
Random access memory (RAM) stores temporary data for the CPU. A hierarchy of RAM sizes optimizes access speed and predicts reuse.
Motherboard
Also known as the mainboard or system board, and lovingly referred to by some as the mobo, the motherboard holds all the other components of your computer in place like a Lego baseplate. It allows them to communicate and gives them life by transferring electricity from the power supply.
Specifically, the motherboard connects to the central processing unit (CPU), which processes instructions for software applications, the random access memory (RAM), and other expansion devices. It does so through the Northbridge and Southbridge motherboard components.
Other considerations when selecting a motherboard include its compatibility with the CPU and other components. A motherboard’s chipset functions as a kind of digital glue that only works with specific processor generations, and it relays information between the CPU and the many connected storage and expansion devices.
Processor
The CPU, or central processing unit, is the brain of a computer system. It is responsible for turning inputs into outputs and controlling the speed of a device.
When the CPU receives an instruction, it fetches it from memory. Then, it decodes the binary code into signals that control other parts of the processor. This process is repeated billions of times per second, depending on the clock speed of the CPU.
The CPU communicates with main memory and other chips via internal communication lines called buses. These lines are traditionally divided into address, data, and control buses, each handling different types of signals. However, modern CPUs often integrate these functions into a single SoC (system on a chip) design. This reduces power consumption and speeds up performance.
RAM
RAM is the temporary storage into which your computer loads software applications and data when it’s running. It’s a volatile memory, which means that everything stored in it is lost when the computer turns off.
To access data in RAM, the memory controller sends a column and row address down thin electrical lines on each chip. When the chips detect an address that matches a data request, they respond with the information.
Memory is gathered into modules that plug into slots on the motherboard (in desktop computers, not laptops or tablets or phones, where processor and RAM are soldered in place). The first SIMMs were 30-pin and later evolved into 72-pin formats. The fastest types of RAM are DDR, which performs read/write functions on both the rising and falling edge of each system clock, doubling the performance for a big leap in overall speed.
Graphics Card
The Graphics Card converts the binary data from your CPU into images that are then displayed on the screen. It is responsible for the basic visuals you see, and high-end graphics like 3D rendering used in computer games.
The card can be either an expansion card plugged into a motherboard, or built-in to the CPU. Integrated cards use less power, but have limited graphical capabilities.
Modern GPUs are multifunctional, and can offload complex 3D rendering tasks from the CPU. They may also be used for 2D graphics processing, TV output, and multi-monitor setups. Some are capable of advanced rendering techniques like ray tracing, which increases the realism of video games. They also use cooling systems with fans and heat sinks to prevent overheating. The most common brands are Nvidia and AMD.
Storage
Various forms of data storage store computer programs and user data. These devices can range from a few GBs to a few or more TB in size. The computer uses an internal bus, coordinated by the northbridge chip, to communicate with memory and high-speed peripherals like PCI, while the southbridge handles communication with slower I/O ports such as storage and USB ports. The system also contains a heat sink, a passive component that draws thermal energy away from components to regulate and reduce their temperature to help ensure they function properly.
Primary storage consists of random access memory and read-only memory that the CPU actively uses, enabling faster program execution. Secondary storage resides on external hard disk drives, CD/DVD units and USB flash drives, which allow for long-term, portable storage of files and applications.