why we need enum in typescript code example

Example 1: declare enum in type script

enum PrintMedia {
  Newspaper = 1,
  Newsletter,
  Magazine,
  Book
}

Example 2: typescript enum value to enum

enum Number {
  One,
  Two
}  

const numberOne: Number = "One" as Number;
const otherNumberOne: Number = Number.One;

const stringOne = Number[Number.One];