note: The cuatro is the name of a family of Latin American instruments found in South America, and in Puerto Rico and other parts of the West Indies. Although some have viola-like shapes, many cuatros resemble a small to mid-sized classical guitar.
Cuatro means four in Spanish; the instruments 15th century predecessor was the Portuguese cavaquinho which has four strings, like the original cuatro (modern cuatros often have more than four strings).