Manchester Encoding (ME):Used by the physical layer in OSI model to encode the signalAlso called Bi-phase ManchesterIf input bit 0: Transition is from Low to highIf input bit 1: Transition from High to LowUsed in ether LAN Differential Manchester Encoding (DME):The transition at the middle bit is used only for synchronization.At 0: transition will be there at the beginning of the bit interval.At 1: transition will be absent at the beginning of the bit interval. NRZ:Non return to zeroVoltage level is constant during a bit interval. Polar Encoding:DME, NRZ and ME all are types of polar encoding.RZ is also one type of polar encoding.