The term energy is so fundamental, but at the same time so frequently used that we hardly ever think about its deeper meaning.
Strictly speaking the word has is origin in physics where it comes in various forms, e.g. as kinetic energy, i.e. the energy connected to a body in motion. Here we have the link to our everyday notion of energy as the driving force of cars, machines etc. That said we tend to think of energy in terms of petroleum, gas, kilowatthours and the like. And indeed all of this makes vehicles move, drives all kinds of machinery and keeps our economy running.
Thus energy is the engine of life. Simultaneously, this engine is fed with various types of fuel. The mixture of these fuels is constantly changing depending on what source of supply we choose or is available.
Energy is a commodity traded in different forms, e.g. as crude oil, natural gas, coal etc. As a consumer we hardly ever think about the primary sources of energy. Instead we are used to getting it in a form which is adapted to our needs, like gasoline, electricity. That is what we pay for. However, the story starts with the primary sources, and it´s there where things may get troublesome. Securing the energy supply must start at the primary level, and these primordial sources constitute the strategic pillars of the entire energy business.