Quick Answer: A T-shirt is a style of fabric shirt named after the T shape of its body and sleeves. Traditionally, it has short sleeves and a round neckline, known as a crew neck, which lacks a collar. T-shirts are generally made of stretchy, light, and inexpensive fabric and are easy to clean. The T-shirt evolved from undergarments used in the 19th century and, in the mid-20th century, transitioned from undergarments to general-use casual clothing. T-shirts are typically made of cotton textile in a stockinette or jersey knit, which has a distinctively pliable texture compared to shirts made of woven cloth. Some modern versions have a body made from a continuously knitted tube, produced on a circular knitting machine, such that the torso has no side seams. The manufacture of T-shirts has become highly automated and may include cutting fabric with a laser or a water jet.