Improving Readabilty of code with Arrow functions

arrowfunc.js

//Normal function
function sum(num1, num2){
  return num1 + num2;
}

let output =sum(10, 4);
console.log(output)

//Arrow function
let sum = (num1, num2) =>   return num1 + num2;
let output2 =sum(10, 4);
console.log(output);

//This keyword