HTTP Status Code 409 indicates a Conflict. This status is returned when a request cannot be completed due to a conflict with the current state of the resource. For example, this may occur when trying to upload a file that conflicts with an existing one, or if a versioning system detects that the resource has changed since it was last accessed. Essentially, it signals that the request could not be processed because it conflicts with another request or the current resource state, and the client may need to resolve the conflict before resending the request.