context-differences.js

var rick = 'Rick';
var morty = 'Morty';
var earth = 'C31';

function rickAndMorty() {
  // global context
  console.log(`These ${this.rick} & ${this.morty} belongs to earth ${this.earth}`);
}

var earthC39 = {
  rick: 'Rick',
  morty: 'Morty',
  earth: 'C39',
  rickAndMorty: function rickyAndMorty() {
    // earthC39 object context
    console.log(`These ${this.rick} & ${this.morty} belongs to earth ${this.earth}`);
  }
}

rickAndMorty();
// These Rick & Morty belongs to earth C31

earthC39.rickAndMorty();
// These Rick & Morty belongs to earth C39