The image shows in parallel two flow types of electric charges, respectively of the movement of electrons in a circuit, these being represented by the alternating current, the first image, and by the direct current, the second image.
The alternating and direct current are illustrated in a diagram with two axes, one vertical, left, of voltage, and another horizontal, down, of time.
The first image shows the flow of electric current, alternating its direction, with oscillations in the form of up and down loops, or in the form of pulses, whose voltage may vary depending on the transformer that transforms this voltage, increasing or decreasing it, so as to be adapted to the needs of the final consumer.
A good example of the use of alternating current is the electricity distribution network through cables and high voltage lines, which are changed to medium or low voltage through the transformer substation before reaching the consumer.
The alternating current is rendered by a wavy, horizontal, thickened line, above another straight line, parallel to it, but thinner, representing the determined time axis.
In the second image is illustrated the one-way direction of the electricity flow, the motion of electrons or ions, thus being called direct current, electric current flowing in a constant direction, distinguishing it from alternating current.
A typical example of direct current use is in a battery.
The direct current is rendered by a horizontal, straight, thickened line, above another line parallel to it, but thinner, representing the determined time axis.