What does a React component represent? code example

Example: class in react

class App extends Component {
    constructor() {
        super()
        this.state = {
            name: "Sally",
            age: 13
        }
    }
    
    render() {
        return (
            

                
{this.state.name}
                
{this.state.age} years old
            
        )    
    }
}