Flux architecture and unidirectional flow

"Hey Mike and Shawn!" entered Carla, on a bright morning.

"Hi Carla, how are you today?"

"Wonderful. The previous app that you build was nice, the clients liked it. They will soon add more features to it. Meanwhile, we have got another small app to build."

"Oh, nice. What are we planning to build?" inquired Mike.

"We need to build a kind of social tracker. To start with, we show a user's reddits, tweets, and so on. We will later extend it to display other information."

"Got it," iterated Shawn.

"Have a good day; I will leave it to you."

"So Shawn, what do you think about the new project?"

"It should be exciting. Umm… can we explore Flux and use it in the app? We had discussed it when we were building the last app."

"Yeah, we can. This will be the perfect opportunity to see how Flux works. Before we start using it, let's go through what Flux actually...