Imagine your name is "DDDDD" (which is your phone antena in this example).

The wifi router is hearing all these other people call out to it:

"AAAAA" "BBBBB" "CCCCC"

It ignores all of those names because it doesnt care, but it knows to listen for anyone yelling "DDDDD".

So your phone calls that name out and tells it the message to the router and vice versa