Weaving is a fabric production process in which two distinct sets of yarns, vertical and horizontal, are interlaced at right angles. Vertical threads are called warp threads and horizontal threads are weft threads. The fabric is usually woven on a loom, a device that holds the warp threads in place while the weft threads are woven through them. If weaving on manual looms appeared in High Antiquity, the mechanized loom appeared during the 18th century in Europe as in America. Today, weaving looms are often programmed using design creation software, which allows, among other things, weaving fabric from photographs as well as digitally produced images and patterns.