A Network Cable Tester is a device used to check the integrity and functionality of network cables. It helps identify issues such as broken wires, incorrect wiring, or connectivity problems in cables like Ethernet or coaxial. By sending signals through the cable, it can determine if the connections are working properly. These testers typically consist of two main parts: a main unit and a remote unit. The main unit is connected to one end of the cable, while the remote unit is connected to the other end. The tester then displays results, allowing users to quickly diagnose and fix any cable issues.