Building REST Services
Standard MVC Controllers return logical "View" template labels mapping to HTML code. REST APIs explicitly return serialized text formats (like JSON).
Consuming REST Services
When your Spring Boot backend needs to fetch external data from a third-party API (like triggering a Stripe payment), it must act as a client.
Securing REST Services
REST services must be explicitly secured because they do not rely on standard browser cookies to track a user's session state.
Spring Data REST and HAL
Normally, linking your Spring Data JPA repositories to a REST API requires building @RestController classes and manually mapping @GetMapping to the repository functions.