Hi Donna, I'll try a really simple explanation just to make it very clear, lots of people (even engineers!) don't really understand frequency. The word "frequency" by itself just means how often something happens - it doesn't matter what that something IS. In science we usually measure how often something happens per second (for consistency). So for example, let's say you are measuring the flow of traffic on a road, and you find that 5 cars pass you every second. Then the frequency (of the traffic) is 5 Hz. The "Hz" stands for "Hertz" which is the unit of frequency - it's just another way of saying "per second". Now in electronics and physics we often have to measure waves. Waves can be waves of water (as in the sea), or waves of sound pressure, or waves of electricity and so on. There are several different things about waves that it's important to measure if you want understand or define the waves, one them is the frequency - i.e. the number of waves that occur every second. The waves, as above can be "made" of different things. For example, obviously waves on the sea are made of water. But in electronics and physics and electrotherapy , we are often concerned with waves made of other things. To explain I'll list some different things below and how the frequency is relevant. 1. Sound. Sound travels in waves. So the frequency of any sound, is the number of waves of sound that occur every second. The waves are actually "made" of whatever the sound happens to be travelling in. That's usually air, but it could also be water or almost any substance. We hear the frequency of sound as tones or notes (as in music) so one musical note has a particular frequency - a different note has a different frequency. Of course we can't hear ALL possible frequencies - some are just too fast or too slow for our ears. The frequencies that are too low are called infrasound , and the ones that are too high are called ultrasound or ultrasonic. The ones we can hear are called audio frequencies. In energetic medicine, sound waves can be applied to cause different effects on the body. Infrasound is like a vibration and can be used as a kind of massage. Ultrasound can penetrate the body and can heat up tissue. Audio sound probably doesn't have any significant medical effect on the body unless of course it's very loud (when it can cause damage) or unless it's musical when it can effect emotional states etc. 2. Electricity. Electricity can be made to flow in waves or switched on and off in pulses. When it is, we have a frequency. If we just switch the electricity on and off we have what are called pulses - but they have a frequency - i.e. the number of pulses per second. If the electricity which is switched on or off is always positive or always negative we call it pulsed DC. The Hulda Clark zapper uses pulsed DC. The "standard" Hulda Clark zapper creates pulses at a rate of 30Khz - what this means is that it switches the electricity on and off 30,000 times per second. This is an "ultrasonic" frequency range but has nothing to do with sound. We only call it ultrasonic because it makes it easier to understand in terms of something we know about from direct experience (i.e. sound). Instead of just switching the electricity on and off we can actually make it change direction a certain number of times per second. So the number of changes per second is again the frequency. When the direction of flow changes from one way to another (i.e. from positive to negative and then from negative to positive) we call it AC or "bidirectional" pulses. the Beck zapper works in this way. The "standard" Beck zapper uses a frequency of 4Hz - what that means is that it changes the direction the electricity flows in, 4 times every second. This is a very low frequency. 3. Electromagnetic waves. These are a bit more difficult to explain. An electromagnetic wave consists of two components - a changing electric field (not an electric current like in a wire - this is like a "force field" of electricity) and a changing magnetic field which are crossed over at right angles to each other. This forms a wave. Now even though all electromagnetic waves work in the same way, there is an enormous range of possible electromagnetic waves - and we tend to classify them into categories, depending on what frequency range they are in. For example in terms of increasing frequency, the following are all electromagnetic waves: radio waves microwaves radar waves infra-red waves visible light waves ultra-violet waves x-rays gamma rays cosmic rays So there is no real difference between a radio wave and a light wave for example - except for the frequency. Light is just "radio" of a much higher frequency. In the light band, the different frequencies of different waves are seen as colours - that is the definition of a colour , light of a particular frequency. In the radio band, different frequencies are like different radio stations. Many electrotherapy devices use different frequencies of electromagnetic radiation. For example, diathermy machines use radio waves. So do some Rife machines. Infra-red machines are used for muscle healing. X-rays and gamma rays are used to attack cancer tumours and for medical imaging etc. In Rife and Hulda Clark work, they both have the theory that diseases can be cured by killing bacteria etc by using frequencies. The idea is that each species of bacteria (also fungus, virus etc) has it's own specific frequency that kills it. To actually do this in practice in means applying electricity to the body which is pulsed at a particular frequency. In some of Clark's work, some electricity (i.e. a voltage) is applied directly to the skin and then switched on and off at a particular frequency that kills a specific bacterium. To kill a different bacterium you just change the frequency of the pulses. Roughly the same principle applies to a pad type Rife device. In a Rife plasma type machine, the idea is similar but slightly different. This machine doesn't apply a voltage direct to the skin with wires - it sends out an electromagnetic wave that "beams" into the body. If you switch this "beam" on or off at a particular frequency then it (supposedly) kills a specific bacterium etc that is sensitive to this frequency. In the case of the plasma type Rife machines there are really TWO frequencies - one is the frequency of the radio waves themselves, the second is the frequency at which you switch the radio waves on and off per second. Imagine switching a light on and off a number of times per second - that's exactly the same thing. The light itself has one frequency (i.e. a colour ) and the number of times you switch it on and off each second is another frequency which is totally unrelated to the frequency ( colour ) of the light itself. The frequency which "kills" is the number of times the beam is switched, not the frequency of the radio wave itself - at least in theory, but there is a complicated relationship between the two in a real Rife machine. Generating the frequencies is easy enough in electronics. There are lots of ways of doing it. One way is to use a computer. The computer can "count" millions or even billions of times per second - so it can generate a specific number of pulses per second - in theory. But there is a drawback to doing it this way. The computer has a kind of fixed internal reference which is called a clock. It can never count faster than the frequency of its clock, and it can only count in whole numbers. So a computer can count 1,2,3,4,5...etc. But it can't count 1,1.1,1.2,1.3,1.4 etc, because these are not whole numbers. By using clever software tricks we can make it LOOK as though it can do this, but in reality it can't. So if we generate frequencies by using a computer's speaker connection we can't generate ANY frequency we want, we can only easily generate frequencies that consist of a count of whole numbers of the pulses of the computer's clock per second. If we want to generate low frequencies - say up to 1600 Hz (1600 pulses per second) a normal PC can do this easily via the speaker and be pretty exact. But as we go higher it gets less and less accurate. By the time we get to 4500 Hz (4500 pulses per second) - the computer can't do this. It can't count EXACTLY 4500 pulses per second through its speaker connection, because relative to the clock it uses for the speaker which is 1843200 pulses per second, there is no way that 4500 will divide exactly into this number and still be a whole number. So the nearest we can get is either 4494 or 4506 - but we can never get 4500. We will always be 6 pulses per second out. If we are looking at a range 10x higher, say 45000 pulses per second we will always be 60 pulses per second out. If you're trying to do Rife work for example, the frequencies need to be pretty accurate. A frequency generator that is 6 pulses per second "out" just isn't good enough. So researchers who know about Rife stuff don't usually try using the computer's speaker connection to do it. If the computer has a sound card, the circuitry is much more sophisticated and CAN generate most frequencies in the range that is normally used in modern Rife work very accurately. BUT the computer is only capable of generating what engineers call "low" frequencies i.e. in the normal sound range and just above it (near ultrasonic). A computer can't generate a light frequency directly for example. For electrotherapy , the frequency is just one part of the equation. You also need to generate the right amount of electricity and often you need to generate a specific shape of wave. if you don't get all these settings just right the therapy may not work - worse there is a possibility it will actually make the disease worse. To answer your question more directly, the frequency alone isn't enough. You need to have the right frequency of the right "thing" whether that is sound, light, radio or electricity to cause the effect you want, and then you have to have the right wave and the right intensity. But in the Rife theory for example, it doesn't matter whether you apply the frequency by means of direct electricity or by means of radio waves - it's supposed to work the same way. That is why Rife people often just talk about "a frequency" without mentioning the specific machine that they use - in theory they should all do the same thing. Of course this isn't always true in practice! :-) In Bob Beck's theory and "standard" Hulda Clark zappers , the frequency isn't important. Their theories are that you can kill the bacteria or whatever just by using some electricity without the frequency being too important. It's only really in Rife work where the frequency is a critical factor. Anyway, I hope that helps - I've tried to make it as simple as possible - some of what I said may be obvious but sometimes it's better to state the obvious than risk any misunderstanding - particularly where people's health is an issue! Best wishes Aubrey