The document provides definitions and formulas for key electrical concepts including voltage, current, resistance, power, energy, static and dynamic electricity, conductors, insulators, semiconductors, and different types of circuits. It defines voltage as the potential difference measured in volts, current as the rate of flow of electric charge measured in amperes, and resistance as a material's opposition to current flow. Formulas are given for calculating voltage, current, resistance, power, and energy in both direct current and alternating current circuits.