The fabric we now know as denim earned its name from the French city where it originated, “serge de Nîmes, translating to “fabric from the town of Nîmes” in France.
Denim is a heavy cotton fabric, also known as jeans fabric. It is woven using a twill weaving technique, a diagonal weaving technique where the threads go over and under each other in a pattern that creates diagonal stripes on the fabric’s surface..
Denim is traditionally known for its characteristic blue colour with white shifts, which is achieved by weaving the fabric with a blue warp and white weft. It comes in many different colours and washes, with blue, black, and grey shades being the most common. We mainly use denim fabric for jeans and workwear.
Sources
FabricLink – Textile Dictionary 
Wikipedia – Denim
Masterclass – What Is Twill Fabric? Definition and Characteristics of theTwill Weave
December 2023, TÄNKOM | Revised March 2024 RETHINK
