Three main types of patents from United States Patent and Trademark Office (USPTO) :
Utility - for new and useful process, machine, manufacture, composition of matter or any new and useful improvement thereof.
Design - appearance of an item is protected. Patent must be an original design for a manufactured item.
Plant - for invented or discovered and asexually reproduced distinct and new variety of plant, including cultivated sports, mutants, hybrids, newly found seedlings, and living organisms.