title: How does Next-auth store session?
body: <p>I have a Next.js project with next-auth hooked up. But I'm confused on how next-auth store sessions.</p>
  <p>On my Chrome cookie, I found this session-token: <code>eyJhbGciOiJkaXIiLCJlbmMiOiJBMjU2R0NNIn0..3_1xKir8Uf2dwky2._druNa1meJemDgeeYw5o6S840s_sW4DShuEu1w34RVAe8cyHm8-ryK5smM1ecKo1KZ_2faPUNpQTwMEUr-AW0Lo_0Oei_n9VIu7xTSET6W0ANdrL2Xg9ZUG9EziZYaW0VFEu.nPkQMkGcrvFRN5BIVvG_ng</code>, but its payload is empty.</p>
  <p>So my question is:</p>
  <ol>
  <li>How is sessionId stored on the client side?</li>
  <li>Does it store only the sessionId or full session data?</li>
  <li>If it only stores the sessionId on client side, then does server-side manages session sharing on multi instances like serverless by default? I'm going to deploy it on Vercel.</li>
  </ol>