Many crowns throughout history have been circlet in style, and today, this is the most popular form of crown used in weddings, rituals, renaissance faires, celtic festivals, and in quality costumes.

Tiara
In modern times the tiara is generally a semi-circular band, (open in the back), usually of metal and decorated with rhinestones or jewels. It is worn by women high on the head, or on the forehead like a circlet.

This style is most likely seen in beauty pagents, but can often be seen as head wear in a wedding ceremony as a bridal tiara. The fictional character Wonder Woman wore a tiara, which also served as a weapon.

Coronet
A small crown consisting of ornaments attched to a metal ring. A coronet never has arches like a crown. A common example of a Coronet is on any of the Liberty Head coins.