This document discusses and classifies various active electronic components. It describes that active components can process or amplify electrical signals and can be classified into tube devices and semiconductor devices. Tube devices include vacuum tubes and gas tubes, while semiconductor devices include junction diodes, Zener diodes, LEDs, BJTs, ICs, and other devices. Transistors are described as semiconductor devices with three terminals that can control current flow. Comparators and timers are discussed as integrated circuits that can compare voltages/currents and implement timing applications. Voltage regulators are also summarized as providing stable output voltages for circuits.