There are three ways to tie a necktie, providing different sizes of knot from small (essential knot), medium (half windsor knot) to large (full Windsor knot).
The option is dependent on fashion and personal choices, and affected by the types of shirt collars.
In general, a essential knot fits tag and pinhole collars, a half windsor knot suits regular collars, and a full windsor knot matchs wide-spread collars (windsor collars); Button-down and short point collars normally tie small or half windsor knot; Wing collars harmonize with bow ties and standup collars go well without any tie.
The diagram consists of mirror images, which is what you would see when you are facing a mirror.
