Does it need to be converted into a JSON object when the data retrieved from the database is responded to the page? Why?

router.get('/api/getArticles', (req, res) => {
  db.Article.find(null, 'title date content', (err, doc) => {
    if (err) {
      console.log(err)
    } else if (doc) {
      res.send(JSON.stringify(doc))
    }
  })
})

I don’t know much about databases, so I may not have asked the right questions, so please give me some advice.