Who is Santa Claus?
Santa Claus, also generallly known as Saint Nicholas, Father Christmas, In many Western cultures,Santa Claus brings gifts to the homes of the good children during the late evening and overnight hours of Christmas Eve, December 24 or on his Feast Day, December 6 (Saint Nicholas Day). The legend may find its origin in hagiographical tales concerning the historical figure of gift giver Saint Nicholas. A nearly identical story is attributed by Greek and Byzantine folklore to Basil of Caesarea. Basil's feast day on January 1 is considered the time of exchanging gifts in Greece.

What does Santa Claus look like?
While Saint Nicholas was originally portrayed wearing bishop's robes, today Santa Claus is generally depicted as a plump, jolly, white-bearded man wearing a red coat with white collar and cuffs, white-cuffed red trousers, and black leather belt and boots. This image became popular in the United States and Canada in the 19th century. This image has been maintained and reinforced through song, radio, television, and films. In the United Kingdom and Europe, his depiction is often identical to the American Santa, but he is commonly called Father Christmas.

Where does Santa Claus live and deos he live alone?
One legend associated with Santa says that he lives in the far north, in a land covered with snow all the year round. The American version of Santa Claus says that he lives at his house on the North Pole, while Father Christmas is often said to reside in the mountains of Korvatunturi in Lapland Province, Finland. Santa Claus lives with his wife Mrs. Claus, a countless number of magical elves, and eight or nine flying reindeer.

Presents for the good children, coal for those naughty?
Another legend of Santa says that he makes a list of children throughout the world, categorizing them according to their behavior ("naughty" or "nice") and that he delivers presents, including toys, candy, and other gifts to all of the good boys and girls in the world, and sometimes coal to the naughty children, on the single night of Christmas Eve. He accomplishes this feat with the aid of the elves who make the toys in the workshop and the reindeer who pull his sleigh.

From and modified: http://en.wikipedia.org/wiki/Santa_Claus