Wireless communication is always interesting. First of all it frees us from wires and increase distance between sender and receiver. You can get lot of advanced RF modules like Zigbee, bluetooth, GSM WiFi. But they are more expensive and not always necessary to have simple RF channel. Simple RF modules may do job well. They cost pennies and are pretty easy to work with. Usually they come in frequencies 315Mhz and 433Mhz. These modules dont have any modulators or encoders. They simply modulate and transmit what ever you give to DATA pin. So obviously some data encoding/packeting mechanism is needed. If microcontroller is used simple USART connection may work pretty well. But this is not very reliable way.
If you want to free MCU from encoding tasks then there are special encoder/decoder chips (HT12E and HT12D) that takes parallel data from MCU and forms data packet to be transmitted. Receiver decodes this packet and produces same signal on output like they were sent using wires. Bhargav shares with details on how to set up transmitter and receiver with decoders and encoders to have simple communication channel. Such setup can be used with any microcontroller pair like Atmega1280 or Arduino.