Rotini is a type of helix- or corkscrew-shaped pasta. The name comes from a 17th-century Italian word meaning "small wheels". Rotini is related to fusilli, but has a tighter helix, i.e. with a smaller pitch. It should not be confused with rotelle ("wagon wheel" pasta).
Rotini originated from Northern Italy and the tight twists help them retain a wide variety of sauces better. They are often used in pasta salads with pesto, Carbonara or tomato-based sauces.
Rotini is most often made from refined (white) wheat flour, although varieties made from whole wheat flour, brown rice, or other grains are also available.
In the US these may also be called colloquially "Scroodle," "Scroodle Noodles", "Scrotini", "Skroodle", "Scroodle Macaroni", or "corkscrews".