Paracetamol.js| #226: Explica este código JavaScript

let randomNumber = Math.floor((Math.random() * 4))
switch(randomNumber){
  case 0:
  case 2:
    console.log("par", randomNumber)
    break;
  case 1:
  case 3:
    console.log("impar", randomNumber)
    break;
  default:
    console.log("error")
}