> Data flows downwards, actions flow upwards I know I'm nitpicking here, but I always find this phrase confusing, and I think this way of explaining unidirecti

> Data flows downwards, actions flow upwards I know I'm nitpicking here, but I always find this phrase confusing, and I think this way of explaining unidirectional data-flow is problematic for those new to the concept. If you want to persist something from a child component, the message that represents the action contains the data needed to make that state change, which sort of exposes the flaws in the up/down analogy. Unidirectional data flow doesn't have an "up" and a "down". It doesn't even follow a single path. It's more like a ladder with several water slides connected to it. The pool is where the state lives. The slides are the child components. The people are the data. Climbers are performing state propagation. People who are sliding are creating actions. People who are landing back in the pool are updating the state. Edit: no, it's not lost on me that the example I ended up using involves up and down motion--it's just not a very easy concept to convey using real-life analogies (which I think also contributes to the learning curve).