ELI5: Explain Like I'm 5

Action–domain–responder

Okay, let me explain this to you like you're five years old!

Imagine you're playing with your toys and your friend comes over. You want to play a game with her, so you tell her what you want to do (action) - maybe you want to play dress-up or have a tea party.

Then, you tell her where you want to do it (domain) - maybe you want to play in your room or in the backyard.

Finally, your friend responds by saying whether she wants to play that game with you or not (responder).

So, action-domain-responder is just a way of describing a conversation or interaction between two people or things. It's like a formula for how to communicate your ideas and get a response from someone else.