Here the source is at the fan/light and a switch loop runs to the wall switch. The source is wired directly to the fan and spliced through to the switch. With this arrangement the light is controlled with the switch and the fan is hardwired for pull-chain control.
Here 3-wire cable is run from a double-pole circuit breaker and split to supply 120 volts to two sets of receptacles. The neutral wire from the circuit is shared by both. This wiring is commonly used in a 20amp kitchen circuit where two appliance feeds are needed, such as for a refrigerator and a microwave in the same location.
Here a gfci receptacle is added at the end of a row of duplex receptacles for single-location protection. The first outlet is connected to the source and 2-wire cable runs from box to box. All wires are spliced with a pigtail at the devices to pass current from one to the next. The load terminals on the gfci are not used and it does not protect the other receptacles in the circuit.
This diagram illustrates the wiring for a circuit with gfci receptacles followed by an unprotected light and switch. The light switch is connected directly to the source and the load terminals on the gfci are not used.