What does it mean and where did it come from? Perhaps some have wondered about the term. It is easy to look it up. However, there is more to it than you will find on many internet sites.

First, it is an abbreviation for hertz, a term originating in the early 1960s to replace the electronic term cycles per second, or frequently just cycles. It sounds really technical, but it’s not. The term cycle is likely as old as the English language. You get up in the morning, you eat breakfast, go to work, pause for lunch, go back to work and return home, etc. Then, next day, you do the same thing. It is a cycle which occurs at the rate of once a day. Okay, there are variations. There are weekends, holidays and, yes, those wonderful vacations. But you get the point. I’m trying to make this simple.

Specifically, in electricity, it refers to something that happens on a regular time. Mostly, it means the times that the flow of electrons reverse their flow, mostly in wires and mostly per second. If we have a wire going north/south then the electrons flow north then south. If we are referring to house hold electricity, that happens 60 times per second. Hence, the term 60 cycles per second, or cps. Note, each cycle the direction changes twice. So, at 60 Hz, the electrons actually change directions 120 times per second.

Then, one day, somebody, I don’t know who, decided cps is confusing, I don’t know why. I’m not that smart and I figured it out. So they invented the term hertz. If you know why they decided on that, maybe you can tell me on a comment.

At any rate, as we in the science community like to do, they decided on Hz for the abbreviation. The long and the short of it, it is that simple.

How-some-ever, it does get complex in a hurry. In the US, the standard way electricity is moved from one place to another is normally 60 Hz. It has been determined it is an efficient means of transmission. Obviously, there are people who disagree. In some countries, they use 50 Hz. If I had to speculate as to why, I would say it is to keep us from using our appliances in their countries.

In most airplanes, they use 400 Hz. It works good there because they don’t have to transmit the electricity as far and it allows them to make things in the plane smaller and lighter.

Perhaps the general public has gotten used to the term suddenly when the home computer hit the stores. Suddenly, everyone and his or her cousin was using the term megahertz without having an Idea of what it meant. Well, they did figure out that that the higher the megahertz the faster the computer.

Here’s one for you. The first computer I owned ran at 1 MHz, or one million cycles per second. The second one ran at 16 MHz. This is referred to as the clock speed. That’s right, computers have clocks in them. In this case, the electrons do not normally reverse direction. They try to make the clock frequency a square wave.

Da. What is a square wave. Let’s put it this way. If I had a switch, a light and a battery. If I turned the switch on and off one time per second, lighting the light 1 time every second for a half a second, then turned it off half a second, this would truly be a square wave with a frequency of one Hz. When the electricity flows, it flows full voltage for half a second. Then, for a half a second, nothing.

Let’s imagine that you are very fast and you could turn that switch on and off 60 times per second, then you would be generating a 60 Hz square wave. Well, my 1 MHz Vic computer had an electronic clock inside it that electronically switched the electric flow at a rate of 1 million times per second. Now I don’t know about you, but that’s faster than I can do it. And, by today’s standards, that is slower than slow.

Today, they talk in terms of GHz. What is a GHz? That is a clock being turned on and off at the rate of one billion times per second. Let’s get this strait. That is beyond human comprehension, or at least mine.

So. Now that we have this incredibly fast clock, what do we do with it? The clock, as the name implies is used for timing. Most everything that happens in a computer happens at a specific part of the clock cycle, for instance, maybe when the current flows, but it could also be when it stops flowing too. The clock is what insures that everything happens at specific times. Otherwise, it would all happen more or less at random times and the outcome would be totally uncontrolled and unpredictable.

If we go back to my little 1 MHz computer, it performed work by following instructions. Some instructions were completed in one clock cycle, some in two, and some in three clock cycles. In general, we could say the computer could execute at least 330 thousand instruction per second. This was a function of the clock speed. If somehow, we could speed up the clock speed, we could make the computer go faster.

Therefore, over the years, one of the primary concerns of the engineers was to increase the clock speed and making the other parts keep up with the clocks.

So, here I am typing on my Inspiron 24 (2 MHz) at a rate of maybe 50 words per minute. And this machine is waiting on my every keystroke. I would guess well over 99 percent of the time in Idle.