The network cable is the twisted pair of computer terminology. It is the cable connecting the computer network card and the ADSL cat or router or switch. The signal transmitted by the telephone line is the modulated signal. The network card of the computer cannot be recognized. The ADSL cat converts it into a A signal that the network card can directly recognize. Therefore, the ADSL cat connects to the telephone line and connects to the network cable at one end.

Network line characteristics
100Ω cable maximum transmission frequency classification:
Category 3 Cable - 16 MHz (MHZ) Category 5 Cable - 100 MHz (MHZ)
Category 5e Cable - 150 MHz (MHZ) Category 6 Cable - 250 MHz (MHZ)
The structural feature of the local area network cable is that the paired lines are twisted together at a certain torque, which is referred to as a twisted pair.
Twisted pair is a transmission medium similar to a telephone line that is twisted together with each other. Each line is insulated and marked with a color code.