一个简单的比较应该是

反应Js

return(
    <div>
      <p>Hello World</p>
    </div>
)

反应本地

return(
    <View>
      <Text>Hello World</Text>
    </View>
)

React Native没有像div, p, h1等Html元素，相反，它有对移动设备有意义的组件。 详情见https://reactnative.dev/docs/components-and-apis

反应本地

它是一个使用JavaScript构建本地应用程序的框架。 它编译为本地应用程序组件，这使它成为可能 构建原生移动应用程序。 不需要彻底检查你的旧应用程序。你所要做的就是添加React 将本地UI组件添加到现有应用程序代码中，而不必这样做 重写。

js的反应

它既支持前端web，也支持在服务器上运行 构建用户界面和web应用程序。 它还允许我们创建可重用的UI组件。 你可以在React JS中重用代码组件，节省大量时间。

简单的React Js是为web React Native是为跨平台移动应用程序!

这里有一个很好的解释:

Reactjs是一个同时支持前端和服务器的JavaScript库。此外，它还可以用于为移动应用程序和网站创建用户界面。

React Native是一个跨平台的移动框架，使用Reactjs来构建应用程序和网站。React Native编译成本地应用程序组件，使程序员能够用JavaScript构建可以在不同平台(如Windows、Android、iOS)上运行的移动应用程序。

Reactjs can be described as a base derivative of React DOM, for the web platform while React Native is a base derivative in itself, which means that the syntax and workflow remain the same, but components alter. Reactjs, eventually, is a JavaScript library, which enables the programmer to create an engaging and high performing UI Layer while React Native is an entire framework for building cross-platform apps, be it web, iOS or Android. In Reactjs, virtual DOM is used to render browser code in Reactjs while in React Native, native APIs are used to render components in mobile. The apps developed with Reactjs renders HTML in UI while React Native uses JSX for rendering UI, which is nothing but javascript. CSS is used for creating styling in Reactjs while a stylesheet is used for styling in React Native. In Reactjs, the animation is possible, using CSS, just like web development while in React Native, an animated API is used for inducing animation across different components of the React Native application. If the need is to build a high performing, dynamic, and responsive UI for web interfaces, then Reactjs is the best option while if the need is to give mobile apps a truly native feeling, then React Native is the best option.

更多信息请点击:https://www.simform.com/reactjs-vs-reactnative/

React是React Native和React DOM的基本抽象，所以如果你要使用React Native，你还需要React…与web相同，但不是React Native，你将需要React DOM。

由于React是基本抽象，一般语法和工作流是相同的，但你将使用的组件是非常不同的，因此你需要学习这些差异，这是内联React，所谓的moto，即“一次学习，随处编写”，因为如果你知道React(基本抽象)，你可以简单地学习平台之间的差异，而不学习另一种编程语言，语法和工作流。

React is a framework for building applications using JavaScript. React Native is an entire platform allowing you to build native, cross-platform mobile apps, and React.js is a JavaScript library you use for constructing a high performing UI layer. React.js is the heart of React Native, and it embodies all React’s principles and syntax, so the learning curve is easy. The platform is what gave rise to their technical differences. Like the browser code in React is rendered through Virtual DOM while React Native uses Native API’s to render components on mobile. React uses HTML and with React Native, you need to familiarize yourself with React Native syntax. React Native doesn’t use CSS either. This means you’ll have to use the animated API which comes with React Native to animate different components of your application.

最重要的是，React是为你的web界面构建动态，高性能，响应性UI的理想选择，而React Native是为了给你的移动应用程序一个真正的原生感觉。

雷夫:what-is-the-difference-between-react-js-and-react-native