CRUD stands for Create, Read, Update and Delete, the four basic operations performed on application data.In REST, each operation is mapped to an HTTP method (POST, GET, PUT/PATCH, DELETE) on a resource URL such as /api/students.It is used because it gives every client (browser, mobile app, Postman) one standard, predictable way to manage data.Spring Boot implements it with @RestController, a service layer and a JPA repository that talks to MySQL.
Features
- One URL per resource, with the HTTP method deciding the action
- Standard status codes: 201 Created, 200 OK, 204 No Content, 400, 404, 409
- JSON request and response bodies
- Validation of input and duplicate-email checks
- No SQL needed, since JPA generates the queries