The first modern computers were built in the 1940s but they were not only primitive by today’s standards but also took up an incredible amount of space.
The first computer that was a clear ancestor of the PC sitting on your desk today was the Altair 8800, released in 1974. It was affordable, relatively compact, and sold in large numbers for its time.
PCs have come a long way since those days but the way they work hasn’t changed that much. Most of the fundamentals for explaining computers applies equally to today and 40 years ago.
Let’s look at how computers operate.
Fundamental Computer Concepts
Understanding a few basic computing concepts helps make a lot of the mysteries of their operation a bit clearer.
Binary Code
First, it’s useful to remember that computers can really only recognize two numbers – 0 and 1. This is known as binary code.
Everything you do with a computer comes down to those two numbers. The magic of modern technology comes from the processor’s ability to take large numbers of those 1’s and 0’s and combine them in particular ways.
Computers can’t think, they can only evaluate information. It’s helpful to remember that when you run into problems, the computer isn’t out to get you — it’s evaluating things in a different way than you would like.
Hardware vs. Software
Hardware and software work together to perform all the tasks that you do on your PC.
Hardware is the physical technology in your computer. This includes memory, storage, the processor, displays, and any other equipment built into the system.
Software refers to the programs and applications running on the computer. Programmers write code that manipulates the hardware to accomplish various tasks — that code becomes software.
Main Components of a Modern PC
There’s lots of specialized computer technology on the market but virtually every computer you use has a few common hardware components.
RAM
RAM, or random access memory, is the memory where the computer stores the software it’s running as well as any data you’re working on.
For example, when you turn on your computer, Windows loads into RAM. When you open a web browser or office application, the program also loads into RAM, along with any files you’re working on.
RAM is what’s known as volatile memory, meaning when you turn off your computer any information stored there disappears. If you want to work on it again the next time you start up, you need to save it somewhere.
CPU
The CPU, or central processing unit, is the chip that does all the processing work. It handles all the calculations and processing actions needed to make all the tasks you do on your computer function.
That could be as simple as converting the code of a web page into what you see in your browser or it could be running millions of calculations per second to keep up with dozens of players in a multiplayer game like Fortnite.
Storage Device
Computers have a limited amount of RAM so they can’t hold every application and file you ever worked on at the same time. A computer’s storage is where those things get saved when you’re not using them.
This storage can be either a hard drive, which uses a spinning disk similar to a CD player, or an SSD which has no moving parts. This is what’s called non-volatile memory, meaning it won’t disappear when the computer gets powered down.
Motherboard
The motherboard is a computer’s main circuit board. All the other components get connected to the motherboard, either directly or through external connections.
Some motherboards have several expansion slots that additional hardware can connect to. These slots get used to expand the RAM, add new features, and upgrade older PCs with newer components.
Video Card
The video card is one of those components. They’re called “cards” because traditionally they were an expansion card that plugged into a slot on the motherboard.
Modern motherboards generally have video support built-in but those integrated video “cards” are generally not very powerful. To run advanced 3D games or other graphic-intensive applications, you’ll likely still need to add a separate video card with a more powerful GPU, or graphics processing unit.
The GPU is similar to a CPU but it’s strictly used for processing the graphics you see on your monitor. With modern high-resolution displays and 3D graphics, the GPU may do almost as much work as the CPU.
Network Interface
One piece of computer hardware that you wouldn’t find in computers older than 25 years or so is a network interface card (NIC). These cards originally added a wired network port that let you plug in an ethernet cable to connect to the internet.
While ethernet connections are still reasonably common, WiFi connections are the most common type of network interface in today’s world.
How the Components Relate to One Another
Now that we’ve covered the important components in a computer and what each of them does, let’s look at how they all work together.
When you load an app on your computer and start working on something, the computer reads the application code from the storage and loads it into RAM. The CPU processes the code in RAM to make the application do its job.
If you load several apps at the same time, the computer may not have enough RAM to load everything at once. In this case, it uses a memory management scheme known as paging to offload some of the information in RAM back to the storage drive.
The operating system decides what to page out to storage based on what application is active and what apps are actively running in the background.
Accessing information on storage drives is much slower than information in RAM so paging will slow things down. This is why having more RAM will make your computer run faster — it can do more before it has to page information out to storage.
When you load an app, the computer tells the video card what to display on the screen. That could be a word processing document or it could be a high-speed, high-resolution 3D game.
Meanwhile, the network interface sends and receives information to and from the internet.
Types of Software
Hardware isn’t the only part of the computer with different types of components. Software comes in different flavors too.
Low-Level Software
Computers have some software built into the motherboard. This software performs simple low-level functions that let the computer start from scratch.
The BIOS, or basic input/output system, is the most fundamental piece of software. It tells the computer hardware how to bootstrap the operating system from the computer’s storage.
The term “booting” your computer comes from that bootstrap process.
Operating System
The operating system (OS) is the software that makes your computer work the way it does. The most common operating systems are Windows and macOS but there are plenty of others as well, including Linux, Unix, CP/M, and MS-DOS.
Applications
Once your computer boots up and loads the OS, you can run applications on top of that. This includes any type of program you use – games, office suites, image editors, video tools, web browsers, etc.
You can even run applications that let you load other operating systems “inside” of the one you’re using. These apps are known as virtual machines and can be a good way of running older versions of your OS or entirely different operating systems without having to reformat your computer to do so.
Do You Need to Know This to Use a Computer?
As you can see, there are a lot of things working together to make your computer do what it does. But do you need to know all this to use a computer?
Not at all, especially in the modern world of technology. If you were using the Altair 8800 back in 1974, you would have needed to know at least some of this to get anything done.
But while it’s not required knowledge now, it can still be helpful to know the basics of how computers operate.
For one thing, if something isn’t working correctly, knowing how the different parts work together may help you narrow down the possible cause. It can also help you to get a handle on new versions of the OS and other applications if you understand the way they relate to one another.
And if you’re buying a new computer, like one of the deals you’ll find here, it’s helpful to understand what the different components and specifications mean. That way, you can be sure to choose a model with the right components for the type of work (or play) you do on your computer.
The Basic Concepts for Explaining Computers Are Pretty Consistent
Computers and technology constantly change as faster, more advanced models get built. But the foundations of explaining computers’ operation don’t change that much from year-to-year or even decade-to-decade.
Now that you understand how all the pieces fit together, hopefully, it will help you become more comfortable with the computers you use every day.
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