Corduroy is a textile composed of twisted fibres that, when woven, lie parallel (similar to twill) to one another to form the cloth's distinct pattern, a "cord." Modern corduroy is most commonly composed of tufted cords, sometimes exhibiting a channel (bare to the base fabric) between the tufts. Corduroy is, in essence, a ridged form of velvet.
The fabric looks as if it is made from multiple cords laid parallel to each other and then stitched together. The word corduroy is from cord and duroy, a coarse woollen cloth made in England in the 18th century.