Resistance (usually denoted by "R") is a physical quantity, which means the magnitude of the conductor's obstruction to current in physics. The greater the resistance of the conductor, the greater the resistance of the conductor to the current. Different conductors generally have different resistances. Resistance is a characteristic of the conductor itself. Resistance will cause changes in the electron flux. The smaller the resistance, the greater the electron flux, and vice versa. Superconductors have no resistance.
The resistance value of the resistance element is generally related to temperature, material, length, and cross-sectional area. The physical quantity that measures the size of the resistance affected by temperature is the temperature coefficient, which is defined as the percentage change in resistance value when the temperature increases by 1°C. The main physical characteristic of a resistor is to convert electrical energy into thermal energy. It can also be said that it is an energy-consuming component, and internal energy is generated when current passes through it. The resistance usually plays a role of voltage division and shunt in the circuit. For signals, both AC and DC signals can pass through resistors.