Understanding the parts of a computer and what they do is essential if you want to build, upgrade, or just get to know your system better. It's where I started many years ago, and it opened up a whole new world for me.
In this guide, I'll walk you through the essential components of a computer and explain what each one does in simple terms.
1. Central Processing Unit (CPU)
The CPU is basically like the brain of a computer. It processes all the information and executes all the tasks required.
It takes information from the RAM and processes it to perform the tasks required from the computer. Some tasks are in pure software form, like work from various applications, while others are executed through other components on the motherboard.
- Executes program instructions
- Processes data from memory
- Controls system operations
- Manages component communication
Learn more about how a CPU works
2. Motherboard
The motherboard is the main PCB that is mounted inside the computer case, and for laptops, it takes up most of the room inside the casing.
All components like the CPU, RAM, storage, and other peripherals are connected to it.
The power supply sends power to it using an ATX connector typically for desktop computers or a barrel connector is commonly used in laptops. The motherboard can then power certain components fully, like the CPU and RAM, while it only provides partial power to other components like the graphics card for certain high-end desktop cards or hard drives connected with a SATA cable to mention two examples.
- Connects all computer components
- Distributes power to hardware
- Enables data transfer between parts
- Houses essential ports and slots
Explore the motherboard in more detail
3. Random Access Memory (RAM)
RAM Stores all the temporary data for a computer system. It keeps all the instructions ready for the CPU to process when necessary.
RAM Specifications are a large contributer to the performance of a computer. The total capacity, channels, frequency, and latency of RAM are the largest factors for performance. The higher the DDR version, gains you access to higher specification model kits. Currently, DDR5 is the best choice.
- Stores active programs and data
- Enables quick data access
- Supports multitasking
- Works with CPU for processing
| RAM Amount | Typical Use | Performance Level |
|---|---|---|
| 8GB | Basic computing, web browsing | Entry-level |
| 16GB | Gaming, productivity | Mid-range |
| 32GB+ | Content creation, heavy multitasking | High-end |
Learn more about how RAM works
4. Power Supply Unit (PSU)
The power supply provides the correct voltage levels of power to all the components inside a computer. It first converts the AC mains supply to DC and then regulates and supplies individual voltage outputs needed by the system.
Various efficiency rating standards are applied to indicate the level of efficiency between the supply and output power. The more effiecient the PSU is, the less power is lost.
- Power supply voltages supplied are typically include: +3,3v, +5v, -12v, +12v, -5v, and +5v.
- They are activated by the motherboard once certain diagnostic pass requirements are met. It can also be overridden by shorting two pins on the ATX connector.
- PSUs Have protection circuit that cut power the moment an irregular load has been detected. The motherboard can also signal the power supply to turn off.
- Choosing the correct Wattage is paramount when considering a new power supply.
5. Graphics Processing Unit (GPU)
The GPU is responsible for creating and displaying everything you see on your screen. It processes visual data, renders images, and handles complex graphics calculations, making it an essential component for gaming, video playback, and visual applications.
GPU's also have their own kind of memory called GDDR (Graphics Double Data Rate). GDDR has high bandwidth capabilities, created specifically for the task.
- Renders 2D and 3D graphics
- Processes video and images
- Supports multiple displays
- Accelerates visual effects
Learn more about graphics cards and how they work
6. Storage Devices
Storage devices are where your computer keeps all your data, programs, and operating system - even when the power is off. Unlike RAM, storage devices retain information permanently, making them essential for saving files and installing software.
There are various storage devices available for internal use in a computer. SSDs in PCIe sockets directly on the motherboard and SSDs and HDDs that connect via SATA cables and separate power connectors from the PSU are most common.
- Stores operating system
- Holds installed programs
- Saves user files and data
- Maintains system settings
7. The Computer Case (Chassis or System Unit)
This is the component that houses all the computer parts and keeps them protected while incorporating some airflow to keep components cool. Most computer cases are made of a pressed metal and with glass or acrylic sections.
PC Cases also have a power switch for turning a computer on, as well as audio connectors such as headphone and microphone jacks, and USB ports. They usually connect up to the motherboard
They can be constructed for different areas of focus. These areas include price, cooling, and aesthetic preference or design style.
- Houses all the internal components
- Comes in various form factors (sizes)
- Provides cooling
- They are constructed for various preferences for cooling and aesthetic appeal
Summary Table
| Component | Primary Function | Essential Fact |
|---|---|---|
| CPU | Processes instructions and data | Known as the "brain" of the computer |
| Motherboard | Connects and powers all components | Contains slots and ports for all major parts |
| RAM | Temporarily stores active data and programs | Higher capacity and speed boost performance |
| Power Supply (PSU) | Converts and distributes power to components | Uses multiple voltage rails (e.g., +12V, +5V) |
| Graphics Card (GPU) | Renders images and outputs display to monitor | Uses GDDR memory for high-speed visuals |
| Storage Devices | Stores files, OS, and applications | SSDs are much faster than traditional HDDs |
| Computer Case | Houses and protects internal parts | Form factor affects airflow and compatibility |
Visual Summary of the Computer Parts
