In the above symbol, the alternating current between the positive wire at the upper wire and the negative wire at the lower wire while the upper wire is negative is called AC voltage.
In other words, the power supplied by an engine (Dinamo) and an inverter is called AC AC. DC power, which is a direct current flowing through a battery, is called DC power. The power generated by the current solar panel is also DC power.
DC power is negative on one side and positive on the other side.