The Half-Windsor Knot, also known as the single Windsor knot,
is a tie knot that is supposed to create a nice triangular knot. Unlike the Windsor knot the Half-Windsor knot is only brought around the loop on one side instead of both sides. The Half-Windsor knot is meant to work best with ties that are wider and made with light to medium fabrics.
The Windsor knot is named after the Duke of Windsor though some believe that it was his father King George V who invented it. Despite the controversy over who invented the knot, the Duke of Windsor is the one who helped popularize the knot as many started to use to emulate the Dukes knot. The Windsor knot is the only tie knot that can be used in by service men in the United Kingdom’s Royal Air Force, though the knot is frowned upon the other armed services services in the United Kingdom’s military.
The Four-In-Hand knot, also known as a Simple knot or as a Schoolboy knot,