what is bind(this) in react

class Foo extends Component {
  constructor(props) {
    super(props);
    this.handleClick = this.handleClick.bind(this);
  }
  handleClick() {
    console.log('Click happened');
  }
  render() {
    return <button onClick={this.handleClick}>Click Me</button>;
  }
}

var name = "uh oh! global";
obj.display = obj.display.bind(obj); 
var outerDisplay = obj.display;
outerDisplay();

// Saurabh