midPHP

How does authentication work in PHP?

Updated May 24, 2026

Short answer

Authentication verifies user identity using credentials, sessions, or tokens.

Deep explanation

Modern authentication uses password hashing, session management, OAuth, or JWTs. Security best practices include CSRF protection and HTTPS.

Real-world example

Enterprise applications use JWT authentication for APIs.

Common mistakes

  • Storing plaintext passwords and weak session handling.

Follow-up questions

  • What is JWT?
  • Why use password_hash?

More PHP interview questions

View all →