Rotini is a type of helix

Helix

A helix is a type of smooth space curve, i.e. a curve in three-dimensional space. It has the property that the tangent line at any point makes a constant angle with a fixed line called the axis. Examples of helixes are coil springs and the handrails of spiral staircases. A "filled-in" helix – for...

- or corkscrew

Corkscrew

A corkscrew is a kitchen tool for drawing stopping corks from wine bottles. Generally, a corkscrew consists of a pointed metallic helix attached to a handle. The user grips the handle and screws the metal point into the cork, until the helix is firmly embedded, then a vertical pull on the...

-shaped pasta

Pasta

Pasta is a staple food of traditional Italian cuisine, now of worldwide renown. It takes the form of unleavened dough, made in Italy, mostly of durum wheat , water and sometimes eggs. Pasta comes in a variety of different shapes that serve for both decoration and to act as a carrier for the...

. The name derives from the Italian

Italian language

Italian is a Romance language spoken mainly in Europe: Italy, Switzerland, San Marino, Vatican City, by minorities in Malta, Monaco, Croatia, Slovenia, France, Libya, Eritrea, and Somalia, and by immigrant communities in the Americas and Australia...

 for twists. It is related to fusilli

Fusilli

Fusilli are long, thick, corkscrew shaped pasta. The word fusilli presumably comes from fusile, archaic or dialectal word for "rifle" , referring to the spiral-grooved barrel of the latter...

, but has a tighter helix, i.e. with a smaller pitch. It should not be confused with rotelle

Rotelle

Rotelle are a type of pasta resembling wheels with spokes. It is similar to Fiori.The name derives from the Italian word for little wheels...

 ("wagon wheel" pasta).

Rotini originated from Northern Italy

Northern Italy

Northern Italy is a wide cultural, historical and geographical definition, without any administrative usage, used to indicate the northern part of the Italian state, also referred as Settentrione or Alta Italia...

 and the tight twists help them retain a wide variety of sauces better. They are often used in pasta salads with pesto

Pesto

Pesto is a sauce originating in Genoa in the Liguria region of northern Italy , and traditionally consists of crushed garlic, basil and pine nuts blended with olive oil and Parmigiano Reggiano and Fiore Sardo...

 or tomato-based

Tomato sauce

A tomato sauce is any of a very large number of sauces made primarily from tomatoes, usually to be served as part of a dish...

 sauces.

Rotini is most often made from refined (white) wheat flour, although varieties made from whole wheat flour

Whole wheat flour

Whole wheat flour is a powdery substance derived by grinding or mashing the wheat's whole grain. It is used in baking but typically added to other "white" flours to provide nutrients , texture, and body to the finished product....

, 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."