Hi Blue,
RD - As the name suggests checks the condition and route to the receiver.
Say, Condition1 is true then the message will be received by Receiver1
else, if Condition2 is true then the message will be received by Receiver2.
ID - Checks the condition and accordingly selects the mapping/interface.
Say, Condition1 is true then the Operational Mapping 1 will be executed.
else, if Condition2 is true then the Operational Mapping 2 will be executed.
Thanks,
Nidhi