The command is used to transmit APDUs from the card to the terminal, which otherwise could not be transferred by the protocol.
The response data depends on the preceding command. Response data is available when it is indicated in the procedure byte, see Table 7.1, or status byte, see Table 7.2. If the command GET RESPONSE is executed, it is required that it is executed immediately after the command it is related to (no other command shall come between the command/response pair and the command GET RESPONSE). If the sequence is not respected, the selected application shall send the status information "technical problem, no precise diagnosis" as a reaction to the GET RESPONSE.
The response data itself is defined in the clause for the corresponding command.
Because there is no interleaving of commands between logical channels, the terminal shall send the GET RESPONSE command on the same logical channel before sending a command APDU in another logical channel. Otherwise, the response is lost.