Christmas is a holiday that's celebrated on December 25th. For religious Christians, Christmas is a celebration of Christ's birth.
In the Western world, may people celebrate Christmas, some of them for religious reasons and others in a more secular way. Christians observe rituals at Christmas including church attendance and reenactments of Bible stories surrounding the birth of Christ. Non-religious observers exchange presents, tell stories about Santa Claus, and usually decorate a lighted Christmas tree. In Old English, it was Cristes mæsse, or "Christ mass." It's been written as a single word since the fourteenth century.