Only certain types of inventions may be patented. The three major types of patents are utility, design, and plant patents, definitions of which appear in the federal statute. If an invention falls within one of the appropriate types of patents, the invention must still be patentable. First, the invention must be novel, meaning no other prior invention description anticipates or discloses the elements of the new invention. Second, the invention must have utility, that is, usefulness. Third, the new invention must not be obvious to those skilled in an art relevant to the invention. The latter requirement is referred to as “nonobviousness.”