Electricity is almost as common as running water in many areas, especially in industrialised countries. Despite this, there is a great deal of ignorance about this strange force and how it comes about. Well, I can reveal that it's all about atoms and the electrons, protons and neutrons they contain.

If you can picture an atom as a sphere, imagine the nucleus in the centre that contains at least one proton and at least one neutron. The proton is positively charged. In orbit around the nucleus is at least one electron which is negatively charged. The reason they have these opposite charges takes us deep into quantum physics. We know that the neutron is made up of quarks and the electron is an elementary particle (it is not made up of anything and is a particle in its own right), but the reason why they have opposite charges is a matter beyond my meagre capabilities and, in any case, this area is at the fringes of human knowledge.

Atoms may contain several protons and electrons. This variation is what separates elements from each other. Although described as sub-atomic particles, electrons have the properties of both particles and waves. In theory at least they could be both at the same time.

If an atom has no electric charge, i.e. it is neutral,  then it contains the same amount of protons as electrons. In some materials - most metals for example - the electrons' orbit around the nucleus is quite loose and they can spin away from the atom. When this happens the atom becomes positively charged because protons are in the majority within the atom. A free electron can join another atom. When this occurs then its new host atom becomes negatively charged because the electrons are in the majority (assuming the atom was neutral in the first place).

The key thing to remember here is that opposites attract. The greater the difference between the number of electrons and protons, the greater the attraction will be. This is called potential difference. If we therefore can manage to produce a negative charge at one end of a copper wire and a positive charge at the other end, free electrons would move towards the positive end. As electrons leave those atoms nearest the positive end, they leave behind positively charged atoms. Electrons from neighbouring atoms will be attracted towards these positive atoms thus creating yet more positive atoms in their wake. This continuing transfer of electrons is called current. The greater the potential difference, or voltage to use its measuring unit, the greater the force of the flow of electrons - or current.

Electricity can be supplied as direct current (e.g. from car batteries) or as alternating current (e.g. household mains).

Often an electrical product requires a different voltage to the one that is supplied from mains electricity. In these cases, a transformer is required. Take, for example, an Insectocutor Fly Killer machine with an electrified grid. This would typically require 4,000 volts in order to operate. These machines have built in Extra High Tension (EHT) transformers that carry out this conversion. The use of transformers is very common along electricity lines and in electrical devices. As well as the step-up transformers that increase voltage - as found in the Insectocutor Fly Killers - transformers can also reduce voltage. These step-down transformers can be found at electricity sub-stations where the very high voltages required to push electrons through long transmissions wires are reduced for local consumption.

And so that is electricity. When you next switch on a light - or an Insectocutor Fly Killer machine - you may just spare a thought for those millions of electrons scurrying around from atom to atom quietly doing their work.