I know UART and serial communication model and data frame. But I want to ask about something else, when I searched in internet just found examples of one Arduino as (receiver) and another Arduino as (transmitter). So my question is how can I implement two Arduino and both of arduinos can communicate each other when after transferring data from one to another (example A->B). If the interpretation of the received data has to be forwarded to the first sender again(B->A).
You sure now
Serial.read(). That's already what you want. A hint to make it clear to you: When using the common
Serial.print() function only the RxD line is in charge an thus only "half" of the serial interface is used. If you connect TxD of arduino A to RxD of another arduino B and RxD to TxD respectively you have full-duplex communication which is what you're asking.