Signal terminators are passive electronic components used to terminate signal lines and prevent signal reflections and interference in high-speed digital communication systems. They match the impedance of the transmission line to the impedance of the connected devices, minimizing signal reflections and ensuring clean signal transitions. Signal terminators are commonly used in serial communication interfaces such as USB, Ethernet, LVDS, and HDMI to maintain signal integrity and maximize data transmission rates over long distances and complex interconnection topologies.