I'm federico and I'm an electronics salesman in a shop. Electronics is a technical science, or engineering science, constituting one of the most important branches of applied physics, which studies and designs structures that process electrical signals, i.e. electrical currents or voltages, which carry information. In this definition the notion of information is considered in the broadest sense: it designates any quantity (physical, such as temperature, sound or speed, or abstract, such as an image, a code...) which can evolve in real time according to a law unknown in advance, or more often provided for this purpose (calculation of Boolean equations). Like all automatisms, electronic systems are often designed in two parts: one, operative, manages the energy-carrying power signals (high currents); the other, informational, manages information-carrying signals (weak currents).