title: What is event.target.value in React exactly?
body: <p>I was able to implement an event handler in my simple React app and I wanted to understand event.target.value more deeply. I have a guess, but I wanted to ask others so I can confirm or modify any false understandings.</p>
  <p>So... how are we able to even use event.target.value in React? Does event belong to the <a href="https://developer.mozilla.org/en-US/docs/Web/API/Event/target" rel="noreferrer">Event Web API that I found here</a>? Or is it more of a React thing?</p>
  <p>Here is my code for reference</p>
  <pre><code>import React from 'react';
  import Display from './Display';
  
  export default class Search extends React.Component{
    constructor(props){
      super(props);
      this.state = { userInput: '' };
      this.onSubmit = this.onSubmit.bind(this);
      this.updateInput = this.updateInput.bind(this);
    }
  
    updateInput(e){
      this.setState({userInput: e.target.value});
    }
  
    onSubmit(){
      const title = this.state.userInput;
      console.log(title)
    }
    
    render(){
      return(
        &lt;div&gt;
        &lt;label&gt;
          Movie Search App
          &lt;br&gt;&lt;/br&gt;
          &lt;input type=&quot;text&quot; value={this.state.userInput} onChange={this.updateInput}/&gt;
        &lt;/label&gt;
        &lt;br&gt;&lt;/br&gt;
          &lt;input type=&quot;submit&quot; value=&quot;Search&quot; onClick={this.onSubmit}/&gt;
          &lt;Display /&gt;
      &lt;/div&gt;
      )
    }
  }
  </code></pre>