Patents protect inventions. However, patents protect only certain inventions. In order to be patentable, an invention must fall within one of four categories of patent-eligible subject matter: articles of manufacture, machines, processes, and compositions of matter. 35 U.S.C. §101. There are some things that are not patentable (i.e. are patent-ineligible subject matter): laws of nature, natural phenomena, and abstract ideas.
In 2014, in Alice Corp. Pty. Ltd. v. CLS Bank International, 573 U.S. 208, 216, 219 (2014), the Supreme Court established a two-part test to determine whether an invention is patent-eligible. In the first step, a determination is made as to whether the claimed invention falls within one of the categories of patent-ineligible subject matter. If it does, the second step is performed: a determination of whether the claimed invention has an inventive concept that transforms the patent-ineligible subject matter into something patentable.