The Incas used knotted cords known as quipu (or khipu) for keeping records. The terms "quipu" and "khipu" are simply spelling variations on the same word. Each "chasqui" carried two items, a quipu and a pututu. A completely different system is that of the quipu, which recorded numbers on knotted strings. A "quipu" could have only a few or thousands of cords. The Inca used quipu or bunches of knotted strings, for accounting and census purposes. A "quipu" usually consisted of cotton or camelid fiber strings. The exact use of quipu in this and later Andean cultures has been widely debated. "Quipu" is the Spanish spelling and the most common spelling in English. "Quipu" is a Quechua word meaning "knot" or "to knot".