With JWT authentication, the server doesn't remember you, you carry proof. After login, the server signs a token containing your identity and hands it back. Your app sends that token with every request, and the server only needs to check the signature to trust it.
Because verifying a signature requires no session storage, any server with the secret (or public key) can authenticate you, which is why JWTs are everywhere in APIs and microservices. The tradeoff: a token is valid until it expires, so expiry times and refresh flows matter.