Mounting

In React JS, the term "Mounting" refers to a stage in the component lifecycle where the React component instance is created and inserted into the DOM. This means that the component is rendered for the first time and the necessary setup for it is done in this phase. It is during this phase that methods like `constructor()`, `static getDerivedStateFromProps()`, `render()`, and `componentDidMount()` are invoked, in this exact order.

Let's see an example of a component mounting in React:

```javascript
class ExampleComponent extends React.Component {
constructor(props) {
super(props);
this.state = { message: 'Hello, World!' };
}

componentDidMount() {
console.log('Component mounted');
// You can make API calls or setState here.
// Any additional setup can be done.
}

render() {
return (
<div>
<p>{this.state.message}</p>
</div>
);
}
}
```

In the example above, when `<ExampleComponent />` is rendered to the DOM for the first time, we call it "Mounting". The methods `constructor()`, `render()`, and `componentDidMount()` are called in this order. The `constructor()` method is usually where we define the state of the component, and the `render()` method is where we define what the component displays. The `componentDidMount()` method, which is called after the component is successfully added to the DOM, is where we do things like make API requests or work with JavaScript libraries. In our example, when the component mounts it logs to the console "Component mounted".