What are the main types of authentication you can name?

Main types of authentication:

1. Password authentication — the most common method, where the user enters a login and password.

2. Two-factor authentication (2FA) — in addition to the password, requires a second factor, such as a code from SMS or an authenticator app.

3. Biometric authentication — using fingerprints, facial recognition, or iris scanning.

4. Certificate-based authentication — using digital certificates to verify identity.

5. OAuth and OpenID Connect — protocols that allow authentication through third-party services (e.g., Google, Facebook).

6. Token-based authentication — for example, JWT, where after login, the user receives a token to access resources.

Each type has its advantages and is used depending on security requirements and convenience.