Understanding HTTP Request Methods: Safety, Idempotency, and Cacheability

HTTP defines a set of request methods to indicate the purpose of the request and what is expected if the request is successful.

Each request method has its own semantics, but some characteristics are shared across multiple methods, specifically request methods can be safe, idempotent, or cacheable.

POST and PATCH are cacheable when responses explicitly include freshness information and a matching Content-Location header.