Technology has always been a part of our lives, from building the first clubs and fires to the Space Age and the Information Age. We always learn enough about technology to use it as part of our daily living, but computer technology is one of the least understood parts of our existence. Therefore this series of articles will clarify some of the mysteries of computers.
What are the benefits of learning more about computers? If you are totally satisfied and have no frustrations with your computer, you are part of a very lucky minority! However, like every other type of technology, the more you understand it the better equipped you will be to handle the many issues that can arise. Knowledge is power, after all! You will be able to help yourself better with this information, and you will be able to help, and impress, your friends as well. So let’s dig into the insides of your computer.
This introductory article will talk about the parts of the computer, and the difference between the various parts such as hardware and software, programs and data and memory and storage. Future articles in the series will go more in-depth on these as well as many other topics. Questions and discussions from readers will also be addressed in future articles.
What do you see when you look at a computer system? The most basic modern setup will include four components; the computer itself, a mouse, a keyboard and a monitor. There may be many other additional components such as printers, modems, speakers, microphones, etc. Let’s start with our basic four component system.
It is helpful to consider this model of the computer: The computer itself computes information (processing); we have to provide information into the computer (input) in order to receive new information from the computer (output). Every piece of computer equipment provides one or more of these functions, input, processing and output.
A keyboard and a mouse provide input into the computer. After processing the information the results are output to a monitor or a printer. Some devices can provide both input and output. For instance, we can receive an email from a friend (input from the internet through the modem) and reply to the email (output to the internet through the modem). Or you can create a spreadsheet and save it to your hard drive (input data to the hard drive) and later open the spread sheet from the hard drive (output data from the hard drive). The modem and the hard drive are capable of both input and output, so they are known as input-output (I/O) devices.
Hardware is any device you can physically touch. Every device talked about so far can be physically touched. Software cannot be touched. It is the electronic information created by the flow or absence of an electrical signal. You cannot touch the programs or data used on your computer. You can touch and hold a hard drive, or a CD or a DVD, so these are all examples of hardware. But you cannot touch the flow or absence of an electrical signal, the zeros and ones that make up the binary world of computers. If you can touch it, it is hardware; if you cannot touch it, it is software.
Programs and data are both considered to be software, because they are composed of the flow or absence of electrical signals, the binary zeros and ones that computers process. The words programs and applications are pretty much the same; they are instructions that tell a computer what to do. The data you create might be a document, spreadsheet, graphic, or email.
All software, programs and data, are kept on the computer in one form or another. When you are working on a word processing document, for example, you have loaded the program (word processor) and data (document) into the RAM (Random Access Memory) of the computer. This is where it is kept while the computer is actively processing the information.
But what happens when you turn off the electricity to the computer? There is only an absence of electrical signal, which would be all zeros in the binary world of the computer. So we must have a way of storing the information so we can use it again later. This is why we use the hard drive. But the hard drive does not have electrical current flowing when the power is off, so it uses an equivalent technique. Like the cassette tapes of yesteryear, the hard drive has a magnetic surface that stores information.
Think of a compass, with North and South poles. North and South can be used to represent the zeros and ones the computer processes. Now all the directions between North and South represent the full range of audio signals in a music cassette, but if we saturate those magnetic particles so they are either North or South, that will provide a digital equivalent to the flow or absence of an electrical signal, the zeros and ones of the computer’s world.
Another way to remember the difference between the electronic memory of the RAM and the magnetic storage of the hard drive is to think of the RAM as your desktop and the hard drive is a large filing cabinet. We pull information out of storage in the hard drive/filing cabinet and place it on the desktop/RAM. The more RAM you have, the bigger your desktop and the more items (programs and data) you can have open. The bigger your hard drive, the more information you can store in your filing cabinet. Also, you can have a large file cabinet/hard drive and a small desktop/RAM, which would mean you could store a lot of information but not enough room to open too many at once, or a small file cabinet/hard drive and a large desktop/RAM, which would allow you to have a lot of information open at the same time but not a lot of room to store it. The best scenario, of course, would be to have ample memory and storage.
This has been a lot of information at once, so let’s bring it to a close for now. Here are some questions for you to consider. What are some different types of input devices? What are some different types of output devices? Would an audio CD be considered hardware or software? Would the music on the CD be considered hardware or software? Which would you rather have, more memory or more storage?