Carbon film resistor 
Carbon film resistors (carbon film resistors) were commonly used resistors in the early days. They were made by spraying a layer of carbon film onto a ceramic rod using vacuum spraying technology, and then processing the outer layer of the carbon film into a spiral shape. The resistance value was determined by the number of spirals. The more spirals, the higher the resistance value. Finally, the outer layer was sealed and protected with epoxy resin. Because the resistance error was higher than that of metal film resistors, but they were cheaper. Carbon film resistors are still widely used in various products and are currently the basic components of electronic, electrical, equipment, and information products. 
Metal oxide film resistor 
Metal film resistors (metal-coated resistors) are also sprayed onto ceramic rods using vacuum spraying technology. Instead of carbon films, metal films (such as nickel-chromium) are used to form spiral-shaped paths for other resistances. Precious metals are sprayed at both ends of the ceramic rods. They are more expensive than carbon film resistors, but they have the advantages of low noise, stability, small temperature influence, and high accuracy. Therefore, they are widely used in audio equipment, computers, instruments, defense and aerospace equipment, etc. 
Metal oxide film resistor 
Some instruments or devices need to operate for a long time in a high-temperature environment. If ordinary resistors are used, they may not maintain stability. In such cases, metal oxide film resistors (metal oxide thin-film resistors) can be used. By utilizing high-temperature combustion technology, metal oxide films (such as zinc oxide) are burned on a highly thermally conductive ceramic rod. Other resistances are formed on the spiral of the metal oxide film, and then an unflammable coating is sprayed on the surface. They can maintain stability even at high temperatures, and the power loaded by the oxide film resistor is also very high. They also have the advantages of low noise, stability, and good high-frequency characteristics. 
Square-shaped wire winding resistance 
The square wire-wound resistor (wire-wound resistor) is known as an early sign of cement. It is made by winding resistance wires made of alloys with high resistance such as nickel, chromium, and iron onto alkaline heat-resistant ceramics. The outside is protected by materials that are heat-resistant, moisture-proof, and non-corrosive. The wire resistor body is placed in a ceramic box and sealed with a special non-combustible heat-resistant cement. The difference in the resistance of the non-combustible coated wire-wound resistor is only that the outer coating has changed to silicone resin or non-combustible paint. Their advantages are accurate resistance, low noise, good heat dissipation, and the ability to withstand high power consumption. Most of them are used in the power stage of amplifiers. The disadvantages are small resistance, high cost, inductance, and unsuitable for use in high-frequency circuits. 
Carbon resistor 
Carbon resistors (carbon resistors) apply adhesive pressure to substances with high resistance coefficients such as graphite and carbon, heat them into rod shapes, and then attach wires during the manufacturing process. The resistance value depends on the proportion of carbon powder and the thickness and length of the carbon rod. Their manufacturing cost is relatively low, but they have poor stability and large errors. 
Surface mount resistor

Surface-mount resistors (chip resistors) are a form of metal-glass uranium resistors. The resistive body is a highly reliable plutonium series glass uranium material that is sintered at high temperatures, and the electrodes are made of silver-palladium alloy paste. They are small in size, have high precision, good stability, excellent high-frequency performance, and are suitable for the substrate of precision electronic products. Surface-mount resistors are resistors that combine multiple resistors with the same resistance into one surface-mount resistor, which can effectively limit the number of components, reduce manufacturing costs, and decrease the area of the circuit board. Variable resistors 
The variable resistor, also known as a potentiometer, can change the resistance within a certain range as needed. It is often used in situations where the split connector needs to be moved frequently to change the resistance value, such as in radios, speakers, hot water heaters, etc. A potentiometer generally consists of a resistor body and a movable brush. The resistance adjustment methods include rotation, sliding, plug end, etc. When the brush moves along the resistor body, a resistance value or voltage related to the displacement is obtained at the output terminal. The semi-fixed resistor is a resistor that can finely adjust the resistance value. Similar to the potentiometer, it is an adjustable resistor for the circuit, but is mainly used to adjust a part of the circuit at the end of the circuit to achieve the desired effect. This procedure is all handled by technicians, and once adjusted, it will not be changed.