A smile is a facial expression formed flexing the muscles near both ends of the flexor muscles of the mouth and the mouth is formed. Some people smile with the corner of the eyes of the muscle contraction. Among the people, it is an expression of joy, companionship, joy or pleasure and happiness.

It is not known for barbecue, which is similar to confusing, but in general, involuntary expression of anxiety.

Smiling is something for everyone to understand, regardless of culture, race or religion; it is known internationally.

Cross-cultural studies have shown that her smile is a means of communication in the world, but there are major differences between the two different culture. It may be spontaneous or artificial.