What is SSO (Single Sign-On)?

🔐 SSO = Single Sign-On One login. Access to many apps. A seamless authentication experience across multiple systems with just one set of credentials.

Why It Matters

💡 Imagine logging in once, and accessing Gmail, YouTube, Drive, etc., without logging in again. SSO = Saves Time + Better UX + Stronger Security

Let’s Break It Down — Step 1

👤 User visits Gmail → Gmail sees no login ➡ Redirects to SSO Authentication Server ➡ SSO sees no login → Redirects to Login Page 🔑 User enters credentials

Steps 2-3 — Validation & Token

✅ Credentials validated 🌀 Global session created 🧾 Token generated & handed over to Gmail

Steps 4-7 — Token Verification

📨 Gmail sends token to SSO Auth Server 🔐 Server validates it, registers Gmail 📦 Gmail returns the protected content to user 👏 User is in!

Now What? YouTube!

🎥 User visits YouTube 🙈 YouTube sees: “Not Logged In” 🔁 Sends request to SSO Authentication Server

Steps 9-10 — Already Logged In

👀 SSO Server sees user is already logged in 🔁 Returns token to YouTube

Steps 11-14 — Instant Access

✅ YouTube validates token 🧠 Registers YouTube system 📂 Returns content 🥳 Boom! User gets access instantly!

Recap

🔐 Login once 🔁 Reuse across platforms 🚀 No need to authenticate again 🙌 SSO = Convenience + Security

Let’s Talk!

💬 Over to You 1️⃣ Have you ever implemented SSO in your projects? ⚙️ What was the hardest part? 2️⃣ What's your favorite sign-in method and why?