Computer cables are usually rope-like cables that are stranded by several groups of conductors (at least two in each group). The group is covered with a shielding layer, and some of the entire cable cores are covered with a shielding layer, and some have a shielding layer for each group and the cable core. According to different laying conditions, in order to protect the cable, some computer cables have an armor layer on the outside, and the outer layer is covered with an outer sheath. Computer cables are widely used in power generation, metallurgy, mining, petrochemical, transportation, science and technology defense and other fields, as computer network (DCS system), automatic control system detection devices and instrumentation connection cables.

Optical cable is the abbreviation of optical fiber cable, which is a medium for transmitting optical signals. The core is made of silicon dioxide doped with germanium, phosphorus and other materials, and is cylindrical. The outer cladding is made of pure silica, which refracts the light signal into the core. Optical fiber cables are divided into single-mode and multi-mode. Single-mode only provides one optical path, and multi-mode has multiple optical paths. Single-mode fiber has large capacity and is expensive. At present, the size of single-mode fiber core and cladding is about 8.3μm/ 125μm, the commonly used multimode core is 62.5μm/125μm. Optical fiber cables can only be used for one-way transmission. If two-way communication is required, they should be used in pairs. The domestic fiber optic cable service speed has reached 100Mbps, and service providers say they will eventually increase this number to 1Gbps to 10Gbps. It has the advantages of small size, small weight, low cost, large communication capacity and strong communication ability. Due to many factors, it is currently only used for long-distance and point-to-point (ie, two exchange rooms) communication transmission.