In general, common resistances include: DC resistance, insulation resistance and AC resistance. This article will introduce resistors.
What exactly is a resistor?
Resistance refers to the degree of resistance that current encounters when flowing in a circuit. Usually we use ohms (Ω) to express resistance. The resistor material, length, cross-sectional area, temperature, and other factors affect the size of the resistance.
The purpose of a resistor is to limit the flow of current. Make the components in the circuit work properly. You can also use it to adjust the current and voltage in the circuit.
Adding resistors in series or parallel can change the characteristics of the circuit. To achieve some specific functions. Resistors play a crucial role in electronic circuits.

Introduction to DC resistance
This is about how much something resists electricity when connected to a DC power source. The resistance relies on the characteristics of the component itself. A fixed resistance connects to things like the material, size, and temperature of the part.
In DC circuits, DC resistance is one of the basic components used to limit current and reduce voltage.
Ohm's law calculates its unit, which is ohms (Ω).
In practical applications of measuring the coil resistance of transformers, transformer windings, DC resistance of wires, etc. DC resistance is an extremely important parameter. Typically, we use specialized DC resistance testing instruments to measure it.
Introduction to insulation resistance
Insulation resistance refers to the DC resistance of insulating materials in electrical equipment and electrical circuits under specified conditions.
An important indicator to measure the insulation performance of insulating materials in electrical equipment is. Used to ensure normal operation of the system and personal safety.
Applying a DC voltage determines insulation resistance. We measure the resistance of the leakage current through the dielectric over time.
In practical applications, the larger the insulation resistance value, the better.
We usually measure insulation resistance in megaohms (MΩ).
Factors such as material deterioration, surface adhesion, dust, moisture, etc., will reduce insulation resistance. Therefore, you need to regularly inspect and maintain it. to ensure it remains at the appropriate level.
Introduction to AC resistance
AC resistance is the term used to describe the impedance of an AC path. AC resistance generally refers to impedance. Impedance is the obstruction to alternating current in a circuit with resistance, inductance, and capacitance.
Resistive devices have the same impedance in both AC and DC circuits. If we ignore the coil's internal resistance, the inductance in the circuit has no resistance to direct current. But it exhibits a large AC resistance, preventing changes in current flow.
The above is all about the introduction of DC resistance, insulation resistance and AC resistance.