What Is The Difference Between Raisins, Sultanas, And Currants?

They are all made from grapes, but different types of grapes.

Raisins are dried black fruit, usually from white grapes.  The most common variety is Muscatel in Europe, or Thompson seedless in the USA. The biggest producers, globally are Australia, the USA, Turkey and Greece.

Sultanas are small raisins made from white grapes, usually the Thompson seedless (or sultana) grape variety.  They are very sweet and light gold colour.  Turkey is the main European producer.  They are younger when picked and dried by a different technique than raisins.

"Currants" can refer to different things.  Dried currants are very small, black and seedless.  They are less sweet than raisins or sultanas.  They were originally produced only on the Zante island in Greece, hence the name Zante currant for the variety of grape that gets made into dried currants.  Dried currants (the little black mini-raisins) are NOT the same as fresh currants.  Fresh currants are various colours, but most commonly red, and come from completely different plants (not a grape vine),  genus Ribes, various subspecies.

There are also currant tomatoes and currant trees, unrelated to the above.