Training Trains Internship
Student login
← Firebase learning path
Firebase · Module 2 of 10

Firebase Authentication

Sign users in with email, phone, Google and more.

📖 Key ideas

  1. Providers: email/password, Google, phone OTP, Apple, GitHub, anonymous.
  2. createUserWithEmailAndPassword and signInWithEmailAndPassword.
  3. signInWithPopup(auth, new GoogleAuthProvider()).
  4. onAuthStateChanged listens for login/logout.
  5. ID tokens prove identity to your backend.
💡 Real-life example: Firebase Auth is a security desk issuing ID badges (tokens) once it checks who you are.
ProviderSign-in method like Google
onAuthStateChangedListener for login state
ID tokenSigned JWT proving the user
uidUnique user id