A uniform jacket is a type of clothing that is typically worn by members of the military, police, or other organizations. The two most common types of uniform jackets are blazers and tunics. A BLAZER is a type of jacket that is usually single-breasted with metal buttons and is often made of wool or cotton. A TUNIC is a type of jacket that is usually longer than a BLAZER and is often made of heavier fabrics such as leather or canvas.