A REST API organises a programming interface around resources and REST architectural constraints. Joomla web services let external applications retrieve and modify data over HTTP without using the normal administrator interface.
Resources and requests
A resource has an address, and the method describes an operation. GET retrieves a representation, POST submits data for processing, PATCH commonly updates part of a resource and DELETE removes it. The particular API contract defines fields and supported operations.
Responses include HTTP status, headers and data when needed. JSON is common, but using it alone does not make an interface RESTful. Stateless requests do not mean that authentication is unnecessary.
Joomla web services
For a Joomla integration, inspect available routes and enabled web service plugins. Each request needs the required authentication and operation permissions. A valid token does not grant access to every resource.
Send Joomla credentials over protected connections and keep them out of URLs, browser code and logs. Handle pagination, validation, limits and failures. Retrying writes should not accidentally create duplicate records.
Conclusion
A REST API connects applications through a resource contract. Reliable integration also handles permissions, failures and retries.