A group of transistors, resistors and capacitors that perform a particular electronic function. Circuits may be made of discrete components wired together or be built into a chip. For example, a chip may contain a single circuit, such as a video codec or digital-to-analog converter, or it may comprise an entire subsystem with hundreds or thousands of circuits (see
SoC,
CPU,
codec and
D/A converter).
Circuits Are Hardware
Circuits are always hardware; however, a "software circuit" may refer to a circuit designed in the computer and simulated before being physically manufactured. See
integrated circuit,
discrete component and
chip.