ReSwift is a Redux-like implementation of the unidirectional data flow architecture in Swift. ReSwift helps you to separate three important concerns of your app's components:

State: in a ReSwift app the entire app state is explicitly stored in a data structure. This helps avoid complicated state management code, enables better debugging and has many, many more benefits...
Views: in a ReSwift app your views update when your state changes. Your views become simple visualizations of the current app state.
State Changes: in a ReSwift app you can only perform state changes through actions. Actions are small pieces of data that describe a state change. By drastically limiting the way state can be mutated, your app becomes easier to understand and it gets easier to work with many collaborators.