Raisins are dried grapes. Common Australian varieties are sultanas and muscatels.
Sunbeam say this about their packed raisins which are the most commonly available supermarket variety: "Sunbeam Seeded Raisins are produced from a blend of several varieties, mostly the Muscat Gordo Blanco or Waltham Cross grapes. It requires 4kg of fresh grapes to produce 1kg of Raisins. These varieties of grapes contain seeds which are removed during processing to produce what is termed as a Seeded or Stoned Raisin. No sulphur is added in the drying process of Australian Raisins."
Other types of raisins are and muscatels which are usually sold 'on the vine' and come from muscatel or more correctly Muscat of Alexandria, grapes.