Electronic components that perform functions such as signal transmission, filtering, and impedance adjustment without consuming power in electronic circuits. These include resistors, capacitors, inductors, transformers, filters, connectors, switches, and other passive components that, unlike active components (ICs, transistors, etc.), do not require external power sources and control basic electrical characteristics of circuits without amplifying or converting signals. These fundamental electronic component groups are widely used in control circuits for manufacturing equipment, measuring instruments, power supply circuits, and signal processing circuits.