Introduction to Computers - Computer Basics

The modern computer has transformed how we live, work and play. Few truly understand what goes into them or what makes them tick. To the uninitiated they are an enigma, much like their human counterparts, the wild nerd.

If you would like to understand either, and be able to follow along in later presentations, then we have to dig into and understand some preliminary concepts.

In today's computer basics we're going to explore and explain, at a general level, all the concepts of what makes a computer ... well, compute!

Just before we dive into the main course, there are some terms which we need to become familiar with to help us understand computers.

Computers use bits that are not unlike a light switch, they are either on or off. This represents a one or zero. In computer terms this is known as binary or base 2. Of course us humans use decimal or base 10.

By assembling 8 bits into a byte (kind of like letters for us humans) and putting a bunch of bytes together (words), the computer can encode anything you input, into a language (binary system or code) the computer understands. All this to be able to process, output or store the data.

Side note: there is also the term nibble which is 4 bits or a half byte. If all this eating talk is making you hungry, grab a snack and we'll get back into it!

These bytes can also be built into representative steps in a program or operating system to tell the computer exactly what must be done next. This can either be done in a low level (assembler) language or in a high level (C++, C#, Basic and many more) language. We'll get more into these and what they are in later presentations.


Diving right in; there are four general operations of a computer system:

  • input
  • storage
  • processing
  • output


In order to have the computer do what you want of it, you have to have some method of manipulating or controlling the device. There are many ways of entering information, controlling the computer or individual programs.

Keyboards allow you to type in commands, enter text into word processors (like the blog editor I'm using to write this post!), information into a database, numbers and information into spreadsheets, etc.

The mouse, first used on the Xerox Alto, allows for the control of where the cursor is on the screen. By moving the mouse and clicking say in a word processor, our pointer becomes a flashing beam (cursor) that allows us to then use the keyboard to type something in.

We now have many other devices that are input devices; trackballs, infrared sensors, graphics tablets, digital image and video cameras, video capture hardware, barcode scanners, joysticks, gamepads, microphones, MIDI piano and music controllers, document scanners, webcams, touchpads, electronic pens and whiteboards, to name but a few!


Back in the early days of computing, the only storage that was available were the dreaded punch cards.

Code would be stored on a series of cards (each card representing a bit) that when read in the proper sequence (bytes) would represent a program or data that could be read into the computer, much faster than typing it! Of course if you dropped the stack of cards ... well many cuss words would emanate from thy lips.

Now we have many varied methods of storing our data:

  • RAM (Random Access Memory) and caches offer temporary storage for information being processed (RAM and caches are the only ones here that aren't permanent. Once power is removed, in most cases these are wiped clear.)

These all offer us more permanent storage for our information:

  • ROM (Read Only Memory) - permanent memory that contains all of the code to allow the computer to pull itself up by the bootstraps (boot).
  • hard disk drives and solid state drives
  • CD+DVDROM drives
  • usb sticks

Side note: Hardware including storage can fail and therefore nothing is REALLY permanent. It is really important that you BACKUP your data to another medium other than primary storage (usually hard disk) and put that backup in a safe place. Most people don't realise this until it's too late and LOSE important documents, pictures and information.

Don't let this happen to you, backup your stuff please. I hate seeing clients cry :/


The "brain" of your computer is the CPU or Central Processing Unit. It contains the electronic circuits that make the computer follow instructions from ROM - Read Only Memory (BIOS - Basic Input/Output System) or RAM - Random Access Memory (operating system, software or program)

By following the instructions contained within these, the computer is able to process information.

Contained within the CPU are:

  • Arithmetic Logic Unit - The ALU is responsible for giving your computer it's "intelligence". It can add and compare numbers and make decisions based on different input conditions. This processing is done at gigahertz speeds, allowing billions of math or logic operations per second.

  • Control Unit - This part of the CPU is the traffic cop of your computer, directing information to the proper places, reading and storing information from disks, RAM, ALU etc.


These devices make your information available for you to view and use!

Efficient and light LCD and LED screens have taken over from the big and power-hungry CRTs from days gone by. These displays allow the computer to show you information freshly processed or display the information that you've just input.

Printers are the permanent display output from your computer. Allowing you to have a "hard copy" (real, physical) of the data you were looking at on the screen (soft copy, virtual, in software).

The four different flavours of printers are, Dot Matrix, Inkjet, Laser and now 3D printers. Impact or Dot Matrix printers are rarely used outside of industrial settings now as inkjet printers have taken over most day to day printing functions as they are the most cost effective. Laser printers are mainly used for professional documentation, letters and high quality printing for brochures etc.

It should be noted that higher end inkjet printers, with the right paper, can rival laser printing. This coupled with the inkjets' cost effectiveness has mostly pushed laser printers out of the mainstream printing arena.

New to the scene recently is the 3D printer. This fledgling technology has just started to come into its own after certain key patents have expired. This allows just about any company to make and sell these devices. Commonly using a plastic that melts under low temperature or a laser that solidifies a substance on contact, this type of printer allows you to make all manner of 3D objects. They can be used for rapid prototyping or just gaining insight into the look and feel of an object that can't be had by just looking at a screen.

This technology combined with all of the new materials sciences will see innovation in every conceivable area where used. Imagine soon we'll be able to print, skin for grafting, blood vessels and arteries, possibly organs and this is just the tip of the iceberg for the medical fields. Structures, space exploration, new instruments for probing our world are at our fingertips and this area is rife for an explosion of knowledge that even the advent of computers can't touch!

In Closing

There you have it; these are the basic concepts that go into every modern computer system or laptop that you will find out there. Now that we have those in our heads, we can properly define what a computer is.

Any device that inputs data and processes that data for output to a display or storage, is by definition a computer.

I hope you found this educational and informative. This is an amazing time to be alive and to take part in something that has revolutionized how we live, work and play.