Cables can be divided into electromagnetic wires and general-purpose insulated wires according to their main uses.

The difference between electric wires and cables depends on the specifications of the wire. Generally, conductors with a cross-sectional area larger than 6 square millimeters are called large wires and cables, while those smaller than or equal to 6 square millimeters are called small wires. Insulated wires are also known as fabric wires. However, sometimes cables are also classified theoretically as wires.

1. Ways to distinguish wires

Wire: Consists of one or two soft conductive wires, covered externally with a soft protective layer, used for conducting current with conductive hard alloy molds. There are various types such as solid, stranded, or foil hand-woven. According to the insulation layer, wires are divided into bare wires and insulated wires.

Bare wire is a wire without any insulation or protective layer. Besides being used as transmission lines for electromagnetic energy and information, it can also be used to manufacture prefabricated components and electrode connection wires for motors and household appliances. Generally made of copper, aluminum, copper alloy, aluminum alloy profiles, as well as composite metals like copper-clad steel and aluminum-clad steel. Bare wires not only have excellent conductivity but also certain physical properties such as compressive strength, tensile strength, bending and twisting characteristics, stress relaxation resistance, and wear resistance.

Insulated cables are divided according to their main use into electromagnetic wires and general-purpose insulated wires. General-purpose insulated cables include various connecting wires and installation wires. Electromagnetic wires specifically refer to insulated wires used for making electromagnetic coils or windings.

2. Ways to distinguish cables

1. Cable: Composed of one or more mutually insulated conductive cores placed inside a sealed protective sheath, forming insulated conductors. Additionally, protective armor layers can be added, used for transmitting and distributing electromagnetic energy or electronic signals. The main difference from ordinary cables is that cables have larger specifications and more complex structures.

2. Cables mainly consist of the following four parts.

1) Conductive core:

Made of high conductivity materials (copper or aluminum). Depending on the laying and application requirements for cable flexibility, each core may consist of a single conductor or multiple stranded conductors.

2) Cable insulation:

The insulation material of the cable should have high ground resistance, high breakdown field strength, low dielectric loss, and low relative dielectric constant. Common insulation materials in cables include oil-impregnated paper, polyethylene, high-voltage polyethylene, high-density polyethylene, rubber, etc. Cables are often classified by insulation material, such as oil-impregnated paper insulated wires, polyethylene cables, and high-density polyethylene cables.

3) Sealed protective sheath:

Protects the insulated cable core from damage caused by mechanical equipment, moisture, humidity, chemicals, light, etc. For insulation layers prone to moisture absorption, lead or aluminum extruded sealed protective sheaths are generally used.

4) Protective armor layer:

Used to protect the sealed protective sheath from mechanical damage. Generally, galvanized steel tape, stainless steel wire, copper foil, or copper wire is used as armor wrapped outside the protective sheath (called armored cable). The armored cable layer also serves as an electrostatic shield and prevents interference from external radio waves. To prevent corrosion of the steel tape or stainless steel wire by surrounding media, they are usually coated with tar or wrapped with pre-impregnated burlap or extruded high-voltage polyethylene or polyethylene sheath.

2. According to their main use, cables can be divided into power cables, communication optical cables, and frequency conversion cables, etc. Compared with overhead cables, the advantages of cables are smaller insulation spacing between wires, smaller footprint indoors, underground laying without occupying above-ground indoor space, no impact from surrounding air pollution, higher switching stability, and less impact on safety and the surrounding environment. However, the construction cost is high, and installation and maintenance are relatively inconvenient, with more complex manufacturing. Therefore, cables are mostly used in densely populated and densely networked power grid areas and busy traffic locations; for crossing rivers, seas, or deep-sea laying to avoid using large-span overhead cables. In areas where overhead cables may affect communication or where aesthetics or concealment is required, cables can also be chosen.