**Electricity** is a fundamental secondary energy source produced by converting primary resources like coal, wind, or solar into the movement of **charged particles**, specifically electrons. According to the sources, its physical properties are defined by **voltage (pressure)**, **current (flow rate)**, **resistance (opposition)**, and **power (usage rate)**, which are governed by mathematical principles like **Ohm’s Law**. Historically, understanding progressed from ancient observations of static electricity to the late 19th-century **"War of the Currents"** between Thomas Edison and George Westinghouse, which ultimately established **alternating current (AC)** as the global standard for efficient long-distance transmission.

In the modern era, electricity has evolved from a simple commodity into a **"digital-first" ecosystem** wher ...