How computers work
Computers are arguably the most important invention for humankind since the development of agriculture 10,000 years ago. No other invention has changed the way humans work, play, and explore as dramatically as the computer. Find out about how they work on this tour.
This story was created for the Google Expeditions project by Vida Systems, now available on Google Arts & Culture.
We can now store seemingly endless amounts of data in a very small place, use them to achieve amazing feats, and have the entire sum of humankind's knowledge available in our pockets. But how exactly do they work?
Tap to explore
Parts of a computer
This expedition will concentrate on PCs, short for personal computers. Regardless of the brand, computers generally contain the same hardware (physical parts of the computer).
Tap to explore
PCs have a monitor which displays information, a mouse used to navigate, a keyboard for inputting information, and a central processing unit (CPU) which interprets data.
Tap to explore
Motherboard
The motherboard is a circuit board which connects all the electrical parts of the computer together. Located on the motherboard are the computer's memory, processor, graphics card, sound card, and other essential parts.
Tap to explore
Monitor
The monitor of the computer simply displays information, such as texts and images, almost instantly. The monitor receives instructions from the video card, located on the motherboard.
Tap to explore
Mouse
A mouse is a small device that is used to navigate a pointer displayed on the monitor. Many mice are now wireless, using radio frequency to communicate with a transmitter plugged into the computer.
Tap to explore
Keyboard
Under every key on a keyboard there is an open circuit. Pressing the key closes the circuit and allows a tiny amount of electrical current to travel through. Keyboards have their own processor to interpret which key is being pressed.
Tap to explore
CPU
The central processing unit, also known as the “brain” of the computer, is a type of microprocessor. It interprets information coming from every part of the computer.
Tap to explore
Hard drive
The hard drive stores information in the form of 0s and 1s. This saved information can be photos, music, documents, and even your computer's operating system and programs.
Tap to explore
Optical drive
Some computers have an optical drive, a component which uses lasers to read and interpret data from a CD or DVD. Some of these drives can write data to CDs and DVDs also.
Tap to explore
Microprocessors
The CPU (Central Processing Unit) is where the computer receives information, processes data, and sends instructions. CPUs are tiny circuit boards called microprocessors.
Tap to explore
These circuit boards contain an incredible amount of transistors, each one storing a tiny piece of information. The world around you is a stylized representation of what it looks like inside a microprocessor.
Tap to explore
Transistors
Microprocessors contain a phenomenal amount of transistors. Some of them contain over 2 billion transistors, all located on a chip not much bigger than a postage stamp.
Tap to explore
Decision maker
The transistors work together to make decisions based on user input. These aren’t the same as decisions that we make every day, they are yes or no decisions, which is the language the computer understands.
Tap to explore
Arithmetic/Logic Unit
Microprocessors also perform calculations using the Arithmetic/Logic Unit, or ALU. It processes all of the arithmetic (addition, subtraction, multiplication and division) and logic operations that the CPU needs to do.
Tap to explore
Data
Microprocessors are responsible for moving data from one memory location to another. This data is stored as 2 numbers: either a 1 or a 0. Stringing these numbers together in different orders is like arranging letters to form different words.
Tap to explore
Silicon
Microprocessors are made up of silicon laid out in a specific pattern. One of the most common elements on Earth, silicon is very cheap to produce and is an excellent semiconductor.
Tap to explore
Computer memory
All the computer’s information is stored within the computer’s memory. There are 2 types of computer memory—one that only works when the computer is on and one that stores data even when the machine is shut down. We are inside a stylized representation of a memory chip.
Tap to explore
Binary
Information is stored in the computer’s memory as a series of numbers: either 1 or 0. Each piece of information is stored in a particular place within the memory, almost like a huge room filled with filing cabinets.
Tap to explore
RAM
RAM stands for Random Access Memory. RAM only remembers information while the computer is on and is used for short-term storage. It is easy to change or delete this data. A typical memory chip is smaller than the size of a postage stamp, and can store billions of bytes of data!
Tap to explore
Volatile
RAM memory is considered volatile because when the computer loses power, the data stored there is lost. An advantage of volatile memory is its speed, as it accesses data fast.
Tap to explore
ROM
ROM stands for Read Only Memory, which serves as the computer’s long-term memory storage. Considered nonvolatile memory, data stored here is difficult to modify and slower to access.
Tap to explore
Instructions
ROM holds the information which tells the computer what to do when you switch it on. Usually preprogrammed in the factory, it contains the computer's BIOS (the basic input/output system).
Tap to explore
Input and Output
Computers receive information digitally using a special language made up of 1s and 0s. In fact the word “digital” is a word that originates in the 15th century and it means “numbers less than 10” (which is also why the word “digits” is sometimes used to describe fingers!).
Tap to explore
Binary
Every single piece of information the computer receives, processes, and outputs is done in the form of binary—a language which only uses the numbers 1 and 0.
Tap to explore
On and off
The reason computers use binary is because each little transistor has 2 modes: “on,” represented by 1 and “off,” represented by 0. The billions of transistors that form a processor give it an almost infinite amount of options.
Tap to explore
Input
Input devices give pieces of information to the computer. These include the keyboard, the mouse, the camera, and the microphone. Joysticks and bar code scanners are also input devices.
Tap to explore
Output
Output devices receive information from the computer, process it, and then display that information in a form we understand. Output devices include the computer monitor, printers, and speakers.
Tap to explore
Software
Humans interact with and use computers via software. Software receives information from the user and interprets the information into a format that can be read by both the computer and the user.
Tap to explore
Computers also run an “operating system,” which organizes, displays, and collates all the software in use on the computer.
Tap to explore
Operating system
This piece of software runs in the background at all times. It handles the computer’s most basic processes as well as manages the computer's memory. Most importantly it acts as an interpreter between human communication and binary language.
Tap to explore
Installation
Software needs to be installed onto a computer. This means the information about how it runs and the operations it performs is stored onto the computer’s memory.
Tap to explore
Types of software
Software is used to complete all sorts of tasks. Essential for people to do their jobs, software can help organize data into spreadsheets, send and receive emails, and create graphics.
Tap to explore
Gaming
Of course, computers are widely used for recreation. Any game played on the computer is based on software, whether it be installed onto the computer or played within an internet browser.
Tap to explore
Networking
A computer communicates in binary language. It receives information from input devices such as the keyboard and mouse. Individual computers can also communicate with each other, even over long distances. A network is a group of computing devices that communicate with each other.
Tap to explore
Internet
The internet is the largest network in the world. Researchers estimate there will be 30 billion devices connected to this network by 2020, and not just computers and cell phones.
Tap to explore
Router
Home networks are connected to each other through a device called a router. A household may have tablets, cell phones, and PCs that can all print wirelessly to a printer. This communication is facilitated by the router.
Tap to explore
Modem
The modem serves as the bridge between the home network and the internet. It connects to the cable, telephone, or satellite and the router. Many times the modem and router are combined on the same device.
Tap to explore
Bluetooth
Bluetooth works by transmitting radio waves. This allows devices located physically close to each other to communicate, without cables or wires. Popular devices include headsets, smartphones, and portable speakers.
Interested in Natural history?
Get updates with your personalized Culture Weekly
You are all set!
Your first Culture Weekly will arrive this week.