JWT

A JSON Web Token is a compact, URL-safe way to pass verified information between two systems. It is commonly used for authentication: after you log in, the server sends a JWT that your browser includes with every subsequent request to prove your identity. JWTs are self-contained, meaning the server can verify them without a database lookup.

Think of a festival wristband. You show your ticket once at the gate, get a tamper-proof band, and every bar and stage inside just glances at your wrist — nobody re-checks your ticket. A JWT works the same way: log in once, receive a signed token, and every page or action after that shows the token instead of your password. The signature means it cannot be forged or edited without the server noticing.

Why it matters for your project: if your product has user accounts — a client portal, a members area, a dashboard — something has to keep people logged in securely, and JWTs are one of the standard tools for it. You will not configure them yourself, but they explain behavior you will see: tokens expire, which is why users get logged out after inactivity, and expiry times are a real trade-off between convenience and security worth discussing with your developer.

JWTs travel with API requests to prove who is asking, which is how a dashboard's front end talks safely to its back end. They also pair naturally with OAuth: when a user signs in with Google, OAuth handles the permission handshake and often hands back a JWT as the proof of identity your app carries forward.