Christmas day is celebrated every year on 25 December on account of Jesus Christ birth day . Santa Claus comes on every Christmas Day to give gift to children to make them happy and cheerful.
There are many story on Santa Claus. One story states that Santa Nicholas who was very helpful to society and love to children is called Santa Claus. And as per other story devil Satan who is king of darkness comes on every Christmas day to give gift to poor children to make them happier.
It is believe that Santa comes on Christmas day only to support poor children with gift on Christmas celebration.