Dealing with relational data inside schema (while making model)

authorModel.js

const mongoose = require("mongoose")
const Schema = mongoose.Schema

const BookSchema = new Schema({
  title: String,
  pages: Number
})

const AuthorSchema = new Schema({
  name: String,
  age: Number,
  books: [BookSchema]
})

const Author = mongoose.model("author", AuthorSchema)

module.exports = Author

// module.exports = mongoose.model("author", AuthorSchema)