Dance
Dance is the rhythmic movement of the body in accordance with music. By this definition, any rhythmic movement can be called dance, even walking. What differentiates dance from walking though is the aesthetic appeal. Dance is a form of expression, that can be used as a social interaction or a spiritual performance. It has been incorporated into various sport and martial art activities as well. Some forms of dance are used as interpretation of a specific theme and may not follow any rhythm at all. There are several existing styles of dance, depending on the culture from which is originated and the setting in which it is performed. Some dances are individual expressions while others form a part of a larger setting like a musical or an opera and are executed as a group. In the middle are several styles for couples that serve as social interaction. Dance is not unique to humans, several animals and birds also act out certain rhythmic movements as part of their mating rituals. Whatever be the form of dance, it is meant to be enjoyed by the person performing it. Seeing how dance has evolved as a form of expression among the various cultures, despite the differences, it can be said to be the one unifying feature of the human species.