What is JSON Web Token (JWT)?
A JSON Web Token (JWT) is a compact, digitally signed string that carries claims, such as a user ID, roles and an expiry time, between systems in JSON format. Because the signature can be verified, a server can trust the token's contents without looking up a session in a database.
Why it matters for your business
JWTs make it practical to secure APIs, mobile apps and single sign-on across many services, but they need short expiry times and careful handling, since a stolen token works until it expires.
After a customer logs into a web portal, the server issues a JWT valid for one hour, and the portal sends it with each API request to prove who the user is.