Introducer

Hello, I still can’t understand what those say “introducer device”, I may read the doc 2 or 3 times but I don’t understand. Besides I’m french, and the google translation doesn’t mean anything. Can you explain me what introducer means please. Thanks

Lets say you have three devices A, B and C. B connects to both A and C, but A and C do not connect directly. Now if on A you set B as an introducer, device C will be automatically added to A, such that also A and C are connected. If later on you add a new device D to device B, that new device D will also be added to A automatically.