React Element, Stateless Component, Stateful Component

App.js

import React, { Component } from 'react';
import logo from './logo.svg';
import './App.css';

// Element
const Elemento = <h1>Hello World!</h1>

// Functional Stateless Component
const Component1 = (props) => {
  return <span>{props.name}</span>
}

// Stateful
class App extends Component {
  render() {
    return (
      <div className="App">
        <header className="App-header">
          <img src={logo} className="App-logo" alt="logo" />
          <h1 className="App-title">Welcome to React</h1>
        </header>
        <p className="App-intro">
          <Component1 name="Marcio" />, to get started, edit <code>src/App.js</code> and save to reload.
        </p>
      </div>
    );
  }
}

export default App;