Start here. This is the direct spoken answer to practice first.
Overview
The choice is about the complete authentication lifecycle, not whether one option sounds more scalable.
A session-based application authenticates once, stores server-side session state, and sends a session identifier, commonly in a secure cookie. A resource server authenticates each request from a bearer token, commonly in the Authorization header. Sessions fit server-rendered and same-site browser applications well and make immediate revocation straightforward. Bearer tokens fit APIs and delegated access but require careful issuance, validation, expiry, storage, and renewal.