OK, smart stuff. Yes, your first-grade teacher's abacus and your friend's Japanese smart toilet (the one he won't shut up about) are both technically computers, which the Oxford Dictionary defines as "an electronic device for storing and processing data [...] according to instructions given to it in a variable program." But a computer can also be a "person who makes calculations," and we're definitely not getting into the definition of toilet plumbing or abacus beads here.
Especially since the advent of the microprocessor, computers have taken hundreds of forms and appeared as parts of countless devices, from your smart phone to your netbook to your smart fridge. So – with the disclaimer that not every computer under the sun features the same set of parts – let's stick to the basics and get into the key parts of the machines most folks are talking about when they say the word "computer."
Central Processing Unit
Among the most crucial parts of the computer – or the most crucial – is the central processing unit, or CPU. Think of the CPU as the brain and central calculator of the computer. This computer chip, which is made of billions of microscopic transistors and sits on your computer's motherboard, receives, calculates and carries out basic instructions. It also allocates tasks to other chips or parts of the computer.
While desktops and laptops typically use CPUs, smaller devices like smart phones are increasingly likely to use a System on a Chip (SoC), which combines the CPU with other components to increase efficiency.
Computers feature a variety of different types of memory, but all of it serves a fairly universal purpose: To temporarily store data when such storage is needed to achieve intermediate results. Most commonly in modern computers, random access memory (RAM) is utilized. Basically, the CPU offloads program instructions to the memory for as long as a program needs to operate. Once the program or computer shuts down, no data is stored in the memory (perhaps ironically).
Mass Storage Device
If you were surprised that your computer's memory is actually not where your epic archive of college-era MP3s lives, the computer's mass storage device has you covered. This is where data is actually written, stored and accessed for the long term, whether it's your old phone's 32-gigabyte SD card or your new laptop's 1-terabyte of hard-disk storage. When a computer needs to access program or app data or bring up a file that you saved six months (or six years) ago, that data comes from its storage device.
Internal and external hard drives, SD cards, optical disc drives, USB flash drives and even cloud storage are all types of mass storage.
More Parts of a Computer
The parts of a computer and their functions don't end there – after all, what good would a computer be if you couldn't interact with it? That's where input and output devices come in. An input device is any type of device you use to give instructions to a computer. That might include a keyboard (or virtual keyboard), touch screen, mouse, motion-based controls, a video game controller or even a microphone (which allows you to give instructions to your Google Assistant or Amazon Alexa, for instance). An output device, on the other hand, displays the results of the computer's work for viewing. Monitors (both external and built-in), printers and projections are all types of output devices.
Many computers also feature dedicated graphics cards or chips, which focus on rendering video and 3D graphics and delivering them to the screen. If you're a hardcore PC gamer, chances are you rely on a 3D graphics card to run current, resource-intensive 3D games.