A turtleneck is a type of sweater or shirt characterized by a high, close-fitting collar that folds over and covers the neck. This design provides warmth and comfort, making it a popular choice for colder weather. Turtlenecks can be made from various materials, including wool, cotton, and synthetic fibers, and come in different styles, such as fitted or loose. Turtlenecks can be worn by both men and women and are versatile enough to be dressed up or down. They are often paired with jackets, blazers, or worn alone for a chic look. The style has been popularized by various fashion icons and remains a staple in many wardrobes.