"https://react-store-new.s3.amazonaws.com/images/pi…09470137&Signature=QIDo0PLzNVdsrVmNgKwVMkLiybg%3D" code example

Example 1: what is react

This is a formatted version of Komadori's answer 
(https://tinyurl.com/Komadori)
React is a JavaScript library for building user interfaces. 
It is maintained by Facebook and a community of 
individual developers and companies. 
React can be used as a base in the development of single-page 
or mobile applications.

Example 2: react documentation

class Board extends React.Component {
  renderSquare(i) {
    return ;  }
}