PUT //_create/<_id>

PUT is idempotent, meaning that if you send the same PUT request multiple times, it will consistently have the same result. Using PUT here explicitly specifies that you're creating a resource at a specific location. This is why it's the more common choice when you have a known document ID.

POST //_create/<_id>

POST is not strictly idempotent in REST semantics. However, in this particular case with _create, it behaves similarly to PUT because _create itself is designed to fail if the document already exists. You may see POST used in cases where the client is not strictly managing document IDs, but in general, PUT is preferred when you're directly specifying an ID.

for creating documents with specific IDs in Elasticsearch, PUT is usually the preferred approach due to its idempotent behavior, even though both PUT and POST will give you the same result with _create.