Calico is a plain-woven textile of Indian origin, made from unbleached, and often not fully processed, cotton. The material has a coarse texture, but is less thick than Denim.
Calico is traditionally known for the Indian floral print designs glazed on them, although in recent times the fabric has been used with different patterns.
In addition to the Indian fabric, calico also refers to calico cats, which have multi-colored coats of brown, black, and white. Unless you are purchasing calico fabric that's imported from India or from a specialty store, calico typically refers to the color scheme of the outfit, rather than the material.