one-port circuit
electrical network (circuit) or device with a single pair of terminals to connect to the rest of the circuit
capacitor
passive, two-terminal electronic component that stores electrical energy in an electric field
resistor
passive electronic component used for its resistance
voltage source
electrical element which maintains a fixed voltage across its two terminals, regardless of current
inductor
passive two-terminal electrical component that stores energy in its magnetic field
current source
electrical component that conducts a fixed current, independent of the voltage across it