The term 'COIF style' refers to an updo hairstyle, which is a type of hairstyle that involves arranging the hair so that it is pinned up off the neck and face. This style is often seen in formal settings, such as weddings or other special occasions. It is also popular among those who want to create a more sophisticated look. The term 'COIF' comes from the French word for 'CAP, ' which is fitting since the style is often compared to wearing a CAP on the head.