What is SSO(Single Sign-On)?

Imagine you work in an office building. Instead of having a different key for every room — your desk, the meeting room, the printer — you get one keycard at reception. That keycard opens everything.

SSO is exactly that, but for software. You log in once, and every app you need just... opens. No more 10 different passwords for Slack, email, Jira, and your HR tool.

The three players involved are simple:

• You (the user) — you just want to get into the app

• The app (Service Provider) — it needs to know you're allowed in

• The gatekeeper (Identity Provider) — the trusted system that confirms your identity, like Okta or Google

How does it actually work?

When you click "Log in" on any app, here's what happens behind the scenes

1. You visit an app (say, Slack). Slack sees you have no active login.

2. Slack sends you to the gatekeeper (your company's Identity Provider — like Okta).

3. You prove who you are at the gatekeeper — enter your password, maybe confirm on your phone.

4. The gatekeeper issues a pass — a small digital certificate saying "this person checked out."

5. Slack reads the pass and lets you in. Every other app does the same — no new login needed.

That "pass" is called a token. It's signed and tamper-proof, so each app trusts it completely.

That's really all there is to it. SSO removes the need for 10 passwords by replacing them with one trusted login. The apps never handle your password directly — they just receive a small, verified "yes, this is them" from the gatekeeper and open the door.

The main benefit: less friction for you, much better security for the organisation.