MICROCONTROLLER: It takes input and after processing it gives required output.
WATER SENSOR: water sensors are conducting wires. These wires are deep in water. One of these wires is positive voltage or negative and others are input of amplifier circuit.
TRANSFORMER: Here step-down transformer is used to power electronics circuits.
RELAY: relays are electromagnetic switches used to switch high power signal through a small signal.
RF TRANSMITTER AND RF RECEIVER: RF Transmitter And RF Receiver are wireless communication device that used radio frequency as carrier frequency.