Coaxial cable refers to a cable that has two concentric conductors that share the same axis. The most common coaxial cable is composed of insulated copper wire conductors. On the outside of the inner insulation material is another layer of the ring conductor and its insulator. The entire cable is then sheathed with a PVC or Teflon sheath.
The coaxial cable can be divided into baseband coaxial cable and broadband coaxial cable (ie, network coaxial cable and video coaxial cable) from the purpose of use. The coaxial cable is divided into 50Ω baseband cable and 75Ω broadband cable. The baseband cable is subdivided into thin coaxial cable and coarse coaxial cable. The baseband cable is only used for digital transmission and the data rate can reach 10Mbps.