What does a JWT token consist of?

JWT (JSON Web Token) consists of three parts, separated by dots:

1. Header — contains information about the token type (usually "JWT") and the signing algorithm (e.g., HS256).

2. Payload — contains claims, which are data about the user and other information, such as an identifier, token lifetime, etc.

3. Signature — created by applying the signing algorithm to the encoded Header and Payload using a secret key or private key.

Each part is encoded in Base64Url and combined with dots:

header.payload.signature

This allows for secure transmission of information and verification of the token's authenticity without needing to store state on the server.