What is computer hardware?

Have you ever wondered what is on the inside of your computer? This video from HowStuffWorks will take you on a virtual tour of a desktop computer.

"Now that's some serious hardware."

It's the kind of line you expect to hear in an action movie, when Arnold Schwarzenegger gets his hand on an arsenal of guns and explosives. Often, the same phrase is applied to the world of computers, though. Want to play the latest video games? You better be packing some serious hardware. That machine built for video editing? It's packing some serious hardware! But what is computer hardware, anyway?

Short answer: Computer hardware consists of the physical components that make a computer go. Software, on the other hand, is the programming that tells all those components what to do. Windows and Photoshop and Web browsers are software. Knowing how to operate software is a bit like knowing how to drive a car: It's what you use the computer for on a daily basis. But understanding hardware is like knowing how the car works. If you can differentiate between serious hardware and ho-hum hardware, you won't overspend on a mediocre computer (or buy one way more powerful and expensive than you need).

We all know hardware describes the physical pieces that make a computer hum with life. But what are those individual pieces? Well, you've probably heard of the processor, or central processing unit(CPU). That's the heart of the computer. It's a chip that takes instructions from programs (software), makes calculations and spits out the results. It may be the most important part, but it's certainly not the only one -- and like understanding the parts of a car, understanding computer hardware could help you repair one when things go wrong.

The Building Blocks of a Computer

Today's CPUs are tiny, but they're capable of massive, speedy calculations.
Today's CPUs are tiny, but they're capable of massive, speedy calculations.

By the 1980s, computers were small enough to fit into our homes, but still too expensive and specialized for the average person to put together. That really changed in the 1990s and 2000s, and now computers are shockingly easy to assemble with the right parts, a little patience and a screwdriver.

There are some basic pieces that go into every computer. A case, or tower, holds all the components, with a large open area that fits a motherboard. Think of the motherboard as the computer's nervous system: It's a big slab of fiberglass etched with circuitry that connects each component of a computer together. Every piece of computer hardware will connect to the motherboard.

Cases also include fans for keeping a computer cool, and room for a big power supply unit, or PSU, that handles power conversion for all the parts of a computer. Random access memory (RAM) is an integrated circuit that stores data in such a way that it's quickly accessible to the processor. Hard drives and solid state drives store gigabytes or terabytes of data using different technologies. A graphics card is its own little ecosystem, with a processor dedicated to different tasks than the CPU and high performance RAM. And that's just about all it takes to make a computer go. When the processor is plugged into the motherboard, a heat sink rests on top to keep it cool.

Today's parts are better labeled, today's cases are more accessible, and computer hardware is cheaper than ever, but the actual makeup of a PC really hasn't changed much.

The Evolution of Computer Hardware

The basic components of a personal computer are more or less the same today as they were in the 1990s. Well, perhaps "less" rather than "more." Parts still perform the same overall functions as they once did. The motherboard still serves as the computer's central hub, with everything connecting to it; the processor still follows instructions; RAM still stores data for quick access, and hard drives still store data long-term. The way those pieces are connected and how quickly they operate has changed tremendously, however.

Many people who talk about improvements in computers reference Moore's Law, which essentially states the number of integrated circuits in microprocessors will double within every two years. The more integrated circuits, or transistors, a chip has, the faster it's going to be. But that's only one thing that makes computers faster and better. For example, the magnetic storage of hard drive disks has increased tremendously since the 1990s. We measure drives in terabytes when we used to measure them in megabytes. New interfaces for transmitting data also make a big difference. The Parallel ATA systems topped out at a speed of 133 MB per second, while Serial ATA, or SATA, currently supports up to 6 gigabits per second (768 megabytes).

Recently, computers have begun to use solid state or flash memory technology to store data instead of hard drives, enabling computers to access data even faster. Since the rise of the smartphone, computer hardware has gotten smaller than ever. But even in the smartphone space, a lot of the same components are doing the same jobs they do in full-size computers.

Different Types of Computers

While laptops, tablets and smartphones all have different form factors, their internal components are quite similar.
While laptops, tablets and smartphones all have different form factors, their internal components are quite similar.

Laptops, desktops, smartphones, tablets: Their use cases couldn't be much different, could they? We use computers in more places and ways than ever before. But the internal components that make that possible are very similar. In most cases, they're just smaller.

Intel manufactures ULV, or ultra low voltage, processors for thin-and-light notebooks which run on less wattage than its regular laptop chips. Laptops also use smaller RAM and hard drives than desktops. Some laptop makers, like Apple, even solder solid state memory right onto the motherboard instead of including a hard drive, which saves even more space.

Phones and tablets have to be incredibly compact. Instead of a motherboard, the heart of a mobile device is a system-on-a-chip, or SoC. The SoC integrates everything -- processor, graphics processor, RAM, interfaces like USB, interfaces for audio, and more -- onto a single board. Of course, touch devices include some hardware that desktop computers don't, like touch controllers for sensing our fingers. Instead of internal power supplies, laptops and mobile devices contain batteries.

But for the most part, they're all computers -- the hardware simply comes in different shapes and sizes.

Author's Note

I've been fascinated with computers since I was a kid, but it wasn't until I was a teenager that I really knew how each component contributed to my computer booting up and playing games. I just liked playing games and messing with Windows! And even when I first started poking around inside them, I found computers intimidating. There are lots of pieces to plug in, and lots of cables to connect, and exposed circuitry looks mighty fragile. But in the 2000s, computer parts manufacturers have done an amazing job making cases far more user-friendly and instructions and pieces easy to follow and put together. With a little research on the parts you need, just about anyone can build a computer these days!

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