The Core Components You Must Have

A working PC needs five things: a CPU (processor), a motherboard, RAM (memory), a storage drive, and a power supply. Everything else—a graphics card, cooling fans, a case—either improves performance or protects these five from damage. You cannot build without all five, and buying the wrong size or type of any one will either waste money or leave you with parts that do not fit together.

The CPU and motherboard are locked together by socket type. A CPU with an Intel LGA1700 socket will not fit a motherboard built for AMD Ryzen. RAM speed and type (DDR4 or DDR5) must match what the motherboard accepts. The power supply wattage must be high enough to run everything you plug into it. Storage connects via SATA or NVMe slots on the motherboard—you need to know which your board has before you buy a drive. Spending 20 minutes matching specs before you order saves the frustration of opening a box to find parts that do not work together.

Key Takeaways

  • You must buy a CPU, motherboard, RAM, storage drive, and power supply—these five are non-negotiable, and they must be compatible with each other by socket type, RAM speed, and connector type.
  • A case protects your parts and holds them in place, but the motherboard size (ATX, Micro-ATX, Mini-ITX) determines which cases will fit it.
  • A graphics card is optional if you only browse and work in documents, but required if you play games or do video editing.
  • CPU cooling comes built into most processors, but a better aftermarket cooler keeps temperatures lower and lets the CPU run faster without throttling.
  • Write down your motherboard model before you shop for anything else—it determines what RAM speed, storage type, and case size will work.

CPU and Motherboard: The Foundation

The CPU is the brain of the PC. Intel and AMD are the only two manufacturers that matter. Intel uses socket names like LGA1700 or LGA1200; AMD uses AM5 or AM4. The motherboard has a matching socket. If you pick an Intel CPU, you must buy an Intel-compatible motherboard. If you pick AMD, you must buy an AMD-compatible motherboard. There is no mixing.

Motherboards also come in three sizes: ATX (full-size, most common), Micro-ATX (smaller), and Mini-ITX (smallest). The size affects which case you can use and how many expansion slots you have. Most people building their first PC buy an ATX motherboard and an ATX case. Write down your motherboard model number before you buy anything else—it is the key that unlocks what RAM, storage, and case will work.

RAM: How Much and What Type

RAM is temporary memory that the CPU uses while running programs. It comes in two types: DDR4 and DDR5. Your motherboard accepts one or the other, not both. The motherboard manual or product page will tell you which type it uses and what speed it supports (measured in MHz, like 3200 MHz or 6000 MHz).

For a PC that browses the web and runs office software, 16 GB of RAM is the standard. For gaming or video editing, 32 GB is safer. You can always add more RAM later if you run out, but you have to buy the same type and speed as what you already have. Most people buy two 8 GB sticks (which equals 16 GB total) or two 16 GB sticks (32 GB total) because RAM runs faster when you use two matching sticks instead of one.

Storage: SSD vs. Hard Drive

Storage is where your files and programs live permanently. An SSD (solid-state drive) is much faster than an old hard drive and costs less per gigabyte than it used to. You should buy an SSD, not a hard drive. SSDs connect two ways: NVMe (a small stick that plugs directly into the motherboard) or SATA (a 2.5-inch drive that needs a cable). NVMe is faster and takes up less space. Check your motherboard specs to see how many NVMe slots it has.

For a first build, a 500 GB or 1 TB SSD is a reasonable start. Windows takes about 30 GB, and a few large games or video projects can fill the rest quickly. You can add a second drive later. If you plan to store a lot of video or photos, buy 2 TB from the start—it costs only a little more and saves you the hassle of running out of space in six months.

Power Supply: Wattage and Efficiency

The power supply converts wall power into the right voltage for your PC parts. It needs to be strong enough to run everything you plug in, with some headroom left over. A CPU and motherboard alone use about 65 to 125 watts. RAM uses almost nothing. A graphics card can use 200 to 450 watts depending on the model. A 650-watt power supply is a safe choice for most builds; a 750-watt gives you room to upgrade later.

Buy a power supply from a brand with a reputation: Corsair, EVGA, Seasonic, or be Quiet are common choices. Avoid the cheapest no-name supplies—they fail more often and can damage your parts when they do. Look for an 80+ Bronze rating or better, which means the supply wastes less power as heat. The wattage and efficiency rating are printed on the box.

Case and Cooling: Protection and Temperature

The case holds all your parts and protects them from dust and accidental bumps. It must fit your motherboard size—an ATX case holds an ATX motherboard, a Micro-ATX case holds a Micro-ATX motherboard, and so on. The case also needs to fit your power supply (most do) and your graphics card if you are buying one (check the length). Cases range from $50 to $200; a mid-range case around $80 to $120 is fine for a first build.

Cooling keeps your CPU and graphics card from overheating. Most CPUs come with a basic cooler in the box, and it works fine for everyday use. If you want lower temperatures or plan to run the CPU hard, an aftermarket cooler like a Noctua or be Quiet model costs $30 to $80 and fits in most cases. Graphics cards have their own built-in fans. The case itself should have at least one or two fans to move air through—most cases come with one or two pre-installed.

Graphics Card: When You Need One

A graphics card is optional. If you only browse the web, watch videos, and work in spreadsheets, the graphics built into your CPU (called integrated graphics) is enough. If you play games, edit video, or do 3D rendering, you need a dedicated graphics card. NVIDIA and AMD make the cards that matter. NVIDIA cards are called GeForce; AMD cards are called Radeon.

Graphics cards range from $150 to $1000 or more. A $300 to $400 card plays most games at high settings. A $500 to $700 card plays new games at maximum settings. The card needs a PCIe slot on the motherboard (all modern motherboards have at least one) and enough power from the power supply. Check the card's power requirements before you buy—some need extra power cables from the supply.

Frequently Asked Questions

Do I need to buy Windows or any software?

Windows 11 costs about $120 for a full license, but you can install it for free and use it with a watermark on the desktop. You can buy a license later if you want to remove the watermark. Most other software you need—web browsers, office tools, video players—is free.

What if I buy parts that do not fit together?

Most online retailers let you return parts within 30 days if they are unopened. If you open them and realize they do not fit, you may be stuck with a restocking fee. Before you order, post your parts list on a PC building forum or subreddit and ask someone to check compatibility. It takes five minutes and saves a lot of frustration.

Can I upgrade parts later?

Yes. RAM and storage are the easiest to swap out. A graphics card can be replaced if you want better performance. The CPU and motherboard are harder to change because they are tied together, but it is possible. Plan for the future, but do not overspend on parts you do not need right now.

How much should I spend on my first build?

A basic PC for web browsing and office work costs $400 to $600. A gaming PC costs $800 to $1500. A high-end gaming or video editing PC costs $2000 or more. Start with what you can afford and what you actually need—you can always add a graphics card or more RAM later.

Where should I buy these parts?

Amazon, Newegg, B&H Photo, and Micro Center are common choices. Prices vary, so check a few sites. Micro Center has the advantage of in-person staff who can answer questions, but not all areas have a store nearby. Local computer shops sometimes have better prices on specific items.