Christmas is an annual festival that commemorates the birth of Jesus Christ, observed primarily on December 25 as a religious and cultural celebration among billions of people around the world. It is preceded by the season of Advent and initiates the Christmas season, which historically lasts twelve days in the West, culminating in the Twelfth Night; in some traditions, the celebration covers an octave. Christmas is a day off from work in many countries of the world. It is celebrated religiously by most Christians as well as culturally by many non-Christians, and is an integral part of the Christmas season. The traditional Christmas narrative in the New Testament says that Jesus was born in Bethlehem in accordance with messianic prophecy. When Joseph and Mary arrived in the city, the inn did not take place, and therefore they were offered a stable where the Child Christ was soon born, and the angels preached this news to the shepherds, who then spread the information. The rituals associated with Christmas in different countries have a mixture of pre-Christian, Christian and secular themes and sources. Popular modern customs of this holiday include handing out gifts, replenishing the Advent calendar or an Advent wreath, Christmasmusic and caroling, rich lighting, creating and viewing Christmas nativity scenes, exchanging Christmas cards, church services, special meal, decoratedChristmas trees, garlands, mistletoe and holly. In addition, the figure of Santa Claus is inextricably linked with these holidays, bringing gifts to children. As gift giving and many other aspects of Christmas are associated with increased economic activity, the holiday has become an important event and a key selling period for retailers and businesses.
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Magnoliophyta, also called angiosperms). The biological function of a flower is to affect reproduction, usually by providing a mechanism for the union of sperm with eggs. Flowers may facilitate outcrossing (fusion of sperm and eggs from different individuals in a population) resulting from cross pollination or allow selfing (fusion of sperm and egg from the same flower) when self pollination occurs. Some flowers produce diaspores without fertilization (parthenocarpy). Flowers contain sporangia and are the site where gametophytes develop. Many flowers have evolved to be attractive to animals, so as to cause them to be vectors for the transfer of pollen. After fertilization, the ovary of the flower develops into fruit containing seeds.
In addition to facilitating the reproduction of flowering plants, flowers have long been admired and used by humans to bring beauty to their environment, and also as objects of romance, ritual, religion, medicine and as a source of food.
The essential parts of a flower can be considered in two parts: the vegetative part, consisting of petals and associated structures in the perianth, and the reproductive or sexual parts. A stereotypical flower consists of four kinds of structures attached to the tip of a short stalk.