Hi this is small post where I’m explaining the ReactDOM.render() that we have in our react applications.
Initially when we create a React application we have this code in the index.js file:
Here we are using the ReactDOM from ‘react‘ that have a method called .render() this method render (visualize) a react element in the passed DOM node, in this case the “id” node.
// React dependencies import React from 'react' import ReactDOM from 'react-dom' // Componentes import App from './App' ReactDOM.render( <App />, document.getElementById('root) )
So, all the result of <App /> component is inserted into the DOM as a child of the div with id “root”
The point where that result (<App />) is inserting into the DOM is what we call mounting a component.
And when React delete your component information from the DOM this is called unmounting
For other changes in the react component this is called Update the component.
By Cristina Rojas.