Unidirectional Flow

Unidirectional data flow means updates move one way: event → action → state update → UI. The UI never mutates state directly.

Flow in practice

• Flux: View → Action → Dispatcher → Store → View
• Redux: dispatch(Action) → reducer → new state → UI

Why it matters

• Clear update path and source of change
• Easier debugging and replay
• Works best with immutable updates