Single Sign-On (SSO): SSO allows users to authenticate once and gain access to multiple microservices without having to log in separately to each one. This is

Short answer: chieved through centralized authentication (e.g., Keycloak, OAuth2, or Okta).

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.