Resistors are commonly referred to as resistors in daily life. It is a current limiting element that, when a resistor is connected to a circuit, the resistance value of the resistor is fixed, usually two pins. It can limit the amount of current passing through the branch it is connected to. A fixed resistor is one whose resistance cannot be changed. A variable resistance is called a potentiometer or variable resistor. The ideal resistor is linear, that is, the instantaneous current passing through the resistor is proportional to the applied instantaneous voltage. A variable resistor used for voltage division. On the exposed resistor, one to two movable metal contacts are tightly pressed. The contact position determines the resistance value between either end of the resistor and the contact. A two terminal device with a definite functional relationship between terminal voltage and current, reflecting the ability to convert electrical energy into other forms, represented by the letter R, in ohms. Actual devices such as light bulbs, heating wires, resistors, etc. can all be represented as resistor components. The resistance value of a resistive component is generally related to temperature, material, length, and cross-sectional area. The physical quantity that measures the influence of temperature on resistance is the temperature coefficient, which is defined as the percentage of change in resistance value for every 3 ℃ increase in temperature. The main physical characteristic of a resistor is to convert electrical energy into thermal energy, which can also be said to be an energy consuming component. Current passing through it generates internal energy. Resistors usually play a role in dividing and diverting voltage in a circuit. For signals, both AC and DC signals can pass through resistors