Medium
Medium refers to the message channel which a sender can use for the purpose of communication. The message channel depends upon the contextual factors as well as the nature of message itself. So basically medium is the choice available with the sender to either write or speak. If the message is long, technical or formal in nature then the sender uses the written channel. On the other hand if the message is urgent or when the immediate response is important then the oral communication is most effective.
Receiver-Decoder
The receiver of the message is also known as decoder, reader or listener. There may be more than one decoder for a single message of the sender. Here we should note that both sender and receiver are influenced by the contextual factors such as culture, internal and external stimuli etc. Every receiver perceives the message in his own way depending upon the type of context he is facing. This results in the miscommunication due to the misinterpretation of information by the receiver. Therefore it is very important for the sender to carefully analyze the contextual factors.
Feedback
When the receiver receives a message he will react with the desired or undesired response. If the receiver clearly understands the message he will give the desired response. Contrary, in case of miscommunication the receiver will give undesired response. The receiver can give feedback in various ways such as oral or written message, an action or simply silence. The success or failure of communication depends upon the feedback given by the receiver.
very good..
good explanation in simple words