PC Anatomy 101: A Beginner’s Guide to Every Essential Part

So, you’ve decided to build your own gaming PC. From all of the conflicting information online about how you should spend your money to researching which components do what to deciding which of those components you eventually want in your build, it can be a bit overwhelming for some people. Fortunately, you're in the right place! In this guide, I'll give you a what's what of PC components and what they do as well as give some brief explanations of which components are good for what purpose. Whether you're chasing the highest frame rates for competitive shooters like Fortnite or Call of Duty, diving into modded RPG worlds, or you're just one of those people that's tired of getting burned by overpriced, cookie-cutter prebuilt systems, this guide is your launchpad into the world of custom rigs.

Building a PC isn’t just about performance. It’s about control. You choose the parts, the look, the airflow, and the upgrade path. And while the process might seem intimidating at first, it’s surprisingly approachable with the right guidance.

Now, let's get into the meat. First, I'll cover each of the main components in your PC and what each of them does:

1. CPU (Central Processing Unit) - The CPU is the "brain" of the computer. It handles all of the instructions that make your computer run. It controls everything from launching games to running all of the tasks in the background that you don't see. Whenever you open a program, type a web address into your browser, or click something with your mouse, the CPU is what interprets those inputs and tells the rest of the components what to do.

   
   

2. CPU Cooler - The CPU cooler is the device that keeps your CPU from overheating. As the CPU works, it generates heat. The cooler transfers the heat from the CPU and dissipates it using a fan or a radiator. Without sufficient cooling, the CPU will slow down or even shut off to protect itself.

   
   

3. Motherboard - The motherboard is the main circuit board in your computer. It's what connects all of the components together so that they're able to communicate and work together to make the PC work. It's the central hub that ties everything in your PC together.

   
   

4. RAM (Random Access Memory) - RAM is your computer's short-term memory. It temporarily stores the data that your system needs "right now," in the moment, like open programs, browser tabs, etc., so the CPU can access them quickly and doesn't have to load them from scratch each time you switch back and forth between them. The more RAM you have, the more tasks your PC can handle at a time without slowing down.

   
   

5. GPU (Graphics Processing Unit) - The GPU handles all the visual output of your computer. It's what's responsible for drawing all of the images, videos, and especially 3D graphics in games. While the CPU manages general tasks, the GPU is built to process thousands of visual calculations at once, making it one of the most essential components for smooth gameplay, high resolutions, and fast frame rates. The more powerful the GPU, the better the graphics performance and more immersive gaming experience you'll have.

   
   

6. Storage (Hard Disk Drive/Solid State Drive) - Your Hard Disk Drive (HDD) or Solid State Drive (SSD) is your computer's long-term memory. It's where your computer keeps all of its data. It stores everything from your operating system and games to documents and downloads. Your storage holds your files even when the computer is turned off, making it essential for long-term data retention and quick access to your programs.

   
   

7. PSU (Power Supply Unit) - The PSU is what gives your computer the electricity it needs to run. It takes power from your wall outlet and converts it into the right voltages for all of the other components. Without a reliable PSU, your system can crash, fail to boot, or even get damaged. Choosing a quality PSU with enough wattage is key to keeping your build stable and safe.

   
   

8. Case - The case is pretty self-explanatory. It's the outer shell that holds and protects all of the components. It provides structure, keeps everything organized, and helps manage airflow to keep parts cool. Cases come in different sizes, colors, and styles. They also offer mounting points for fans, drives, and cables. A good case makes building easier and keeps your system running smoothly and looking clean. The case is also where almost all of your style choices come into play. Some people prefer their case to be a showcase. They want to be able to see all of their components and have lots of lights to accent the aesthetic. Others prefer a stealthier look without being able to see inside and prefer little to no RGB lighting. There is no right or wrong way. It's all about your preference and your style.

There are other components that go into a PC build, but these are the main parts that arguably matter the most.

Now that you have an understanding of which components do what, I'll cover some basic information about how to start choosing which type of components for what purpose.

1. CPU - CPUs come in a range of models designed for different tasks. The key difference often lies in their core count and clock speed. The core count, put simply, is how many CPUs operate on the chip. Even though the CPU in your computer is a single chip, a six-core CPU is essentially six separate processors working at the same time. In some situations, the more cores a CPU has, the more processing it can do at once, which improves things like load times. CPUs with strong single-core performance are ideal for gaming, where many titles rely on fast execution of tasks on only one or two cores, especially in older or competitive games that aren’t optimized for multiple threads. Most modern CPUs have a minimum of six cores, and most games don't make use of more than one or two. Therefore, the number of cores on a CPU in a system that will be used primarily for gaming isn't really an issue. The speed at which each individual core performs is far more important. On the other hand, CPUs with higher core and thread counts shine in workloads like video editing, 3D rendering, streaming, and multitasking, where many processes run at the same time. If you're looking to stream your gaming session or accomplish the other tasks mentioned above, a CPU with more cores is more important. You'll be able to accomplish those tasks using a CPU with fewer cores, but you'll notice a decrease in the speed at which it completes tasks. Choosing the right CPU ultimately depends on what you want your PC to do most efficiently.

   
   

2. CPU Coolers - There are two primary types of CPU coolers, air coolers and all-in-one (AIO) liquid coolers. Both mount directly to the top of the CPU. Air coolers transfer heat through a metal part called a heat sink (usually the part with a bunch of tiny, thin fins) and use a fan to blow air across it to dissipate the heat. AIOs usually have a pump mounted to the CPU that passes liquid through it to transfer the heat off of the chip. That liquid carries the heat to a radiator that has a coil inside it. Typically, multiple fans then blow across this radiator to dissipate the heat and cool the liquid. AIOs are usually more expensive, but offer better cooling performance. They're typically only necessary for CPUs that draw a lot of power.

   
   

3. Motherboard - Motherboards come in different types based on size, features, and intended use. The most common sizes (referred to as the form factor) are ATX, Micro-ATX, and Mini-ITX. ATX boards are full-sized and offer the most expansion slots, ports, and features. They're ideal for gaming and high-performance builds. Micro-ATX boards are slightly smaller, with fewer slots but still suitable for most users who want a balance of capability and compactness. Mini-ITX boards are the smallest and best for compact builds, though they often have limited connectivity and fewer upgrade options. Beyond size, motherboards differ by something called the chipset, which affects which CPUs you can use, whether or not and to what degree you can overclock the CPU, input/output ports (I/O) like USB, USB-C, ethernet, and HDMI, and features like PCIe lanes (data pathways on your motherboard that connect high-speed components like GPUs and SSDs to the CPU, allowing them to transfer information quickly and efficiently). Choosing the right motherboard depends on your case size, what you plan to use the system for, and how much future expansion you want.

   
   

4. RAM - As I mentioned above, RAM is your computer’s short-term memory, storing data that’s actively being used so the CPU can access it quickly. There are different types of RAM - most commonly DDR4 and DDR5. DDR5 offers faster speeds and better efficiency for newer systems, but requires a compatible motherboard and CPU. RAM speed is measured in megahertz (MHz) or megatransfers per second (MT/s), which is how many millions of data cycles or transfers it can perform per second. Higher speeds can improve performance in tasks like gaming, video editing, and multitasking. Latency, on the other hand, refers to how quickly RAM responds to requests. Lower latency means faster response times. While both speed and latency affect performance, the impact varies depending on the workload. Fast RAM benefits memory-intensive tasks, while lower latency can help with responsiveness in real-time applications.

   
   

5. GPU - GPUs vary widely in performance depending on their chip design, core count, data transfer speed, and driver optimization, which affects how well they handle different tasks. For gaming, GPUs with high clock speeds, strong single-thread performance, and drivers that are optimized for DirectX or Vulkan (graphics tools that help games and creative software talk to your GPU) tend to perform best, especially in drawing real-time 3D graphics at high frame rates. In contrast, productivity tasks like 2D design, 3D rendering, video editing, and CAD benefit more from GPUs with higher VRAM (your GPU's short-term memory), the ability to handle multiple tasks at once, and support for professional drivers and tools such as OpenCL or CUDA. Workstation-class GPUs (e.g., NVIDIA Quadro or AMD Radeon Pro) are often preferred for creative and scientific workloads due to their stability and precision, while gaming GPUs (like NVIDIA GeForce or AMD Radeon RX) offer better value and speed for gaming-focused builds. Choosing the right GPU depends on whether your priority is fast, fluid gameplay or reliable, high-quality rendering and compute performance.

   
   

6. Storage - HDDs use spinning magnetic disks and a moving read/write head and typically offer higher capacity at a lower cost per gigabyte, but have slower read/write speeds, more noise, and are less reliable over the long term. SSDs use flash memory with no moving parts, delivering much faster boot and load times, are quieter and more durable, and have better responsiveness for applications and gaming, though they cost more per gigabyte. Some people choose to use both; an SSD for the operating system, frequently used programs, games, and active projects, and an HDD for bulky mass storage, backups, and archives where capacity and cost efficiency matter most.

   
   

7. PSU - Power supplies come in three cable styles: non-modular, semi-modular, and fully modular. Non-modular units have all cables permanently attached with no option to add more, semi-modular units keep essential cables fixed (24‑pin, CPU) and let you add the rest, and fully modular units let you use only the cables you need for a cleaner build and easier cable management. The wattage indicates the total power the PSU can deliver. It's ideal to choose a unit with enough headroom for your components and future upgrades rather than one that just meets the minimum. A good rule of thumb is to get an estimate of the maximum required power draw of your PC and add 100 to 200 watts to the power supply you choose. For most basic builds and budget systems, a non-modular or semi-modular PSU at the correct wattage offers the best value. For compact builds, high-end gaming rigs, or systems where airflow and tidy cabling matter, a fully modular PSU is worth the convenience. Prioritize a reputable brand, an appropriate wattage rating, and at least an 80 Plus Bronze efficiency rating or better for reliability and efficiency.

   
   

8. Case - Cases vary by size and purpose, and choosing the right one depends on your components and priorities. Full‑tower cases offer the most expansion, radiator support, and airflow for high-end workstations and multi‑GPU or enthusiast builds. Mid‑tower cases strike the best balance for most gamers and power users, fitting full‑size GPUs, multiple drives, and standard cooling without taking up too much space. Micro‑ATX cases are smaller and budget‑friendly while still allowing decent expandability for mainstream systems. Mini‑ITX cases are ultra‑compact for small form factor or portable builds but require careful parts selection and limit upgrade options. Also consider features like airflow and fan/radiator support for cooling, GPU clearance and PSU size for compatibility, drive bays if you need lots of storage, and cable management or a modular internal layout for cleaner builds. Choose a full‑tower for expandability and cooling, mid‑tower for versatility, micro‑ATX for compact value, and mini‑ITX when space or portability is the priority.

You may be thinking that the sheer amount of information is exactly why you're hesitant to attempt your first PC build, but now that you’ve seen the essentials, you have a great jumping off point! Now you have an understanding of how different CPUs prioritize single‑core speed or multiple cores for multitasking, motherboard sizes and chipsets that determine expandability, RAM types and why MHz and latency matter, the differences between GPUs for gaming versus creative work, storage tradeoffs between HDDs and SSDs, PSU cable styles and sizing, and case form factors that balance space, cooling, and compatibility. Your next step is determining what you want your PC to do. Once you know that, you have the knowledge to get started. Knowing the intended purpose of you build is how you'll match component strengths to your real needs. Favor single‑core speed for competitive gaming, more cores for rendering and streaming, SSDs for your OS and active projects, and modular PSUs or larger cases when neatness and cooling matter. Plan around the workloads you actually run. If you want, visit my contact page and send me a message. Give me your budget, target games or apps, and preferred case size and I’ll draft a tailored parts list and build plan you can follow step by step. If building your own still seems like too much to big of a task, visit my custom builds page and select as many or as few parts as you choose and I'll get started tailoring a build list specific to your needs. We can discuss what your intended use is, your style choices, or just address any questions or concerns you have.

Ready for the details? Read "Choosing the Perfect CPU for Your Build." When you’re ready, reach out and I’ll help you assemble the perfect parts list. Let's build something great together!