Well I do believe I mentioned this difference.If anyone is interested the Syllabus of Google LLC v. Oracle America, Inc. is online and shows details that should be kept in mind when using it as an example.
As one article put it "The Supreme Court ruling was a mixed bag that many observers are still parsing. In a 6-2 decision, justices sided with Google and its argument that the company’s copying of 11,500 lines of code from Oracle’s Java in the Android operating system was fair use. Great! At the same time, though, the court appeared to be operating under the assumption that APIs are copyrightable."
How the Supreme Court saved the software industry from API copyrights give a summation that mere mortals can read. Despite the title the court didn't throw out the idea that APIs were copyrightable - in fact the Supreme Court ignored that and went straight to Fair Use.
Given the rapidly changing technological, economic, and business-related circumstances, we believe we should not answer more than is necessary to resolve the parties’ dispute," Justice Stephen Breyer wrote in his majority opinion. "We shall assume, but purely for argument’s sake, that the entire Sun Java API falls within the definition of that which can be copyrighted."