Advent is traditionally a time of expectant waiting.
The term Advent is a version of the Latin word adventus, meaning "coming". It is unknown when the period of preparation for Christmas that is now called Advent first began. It was certainly in existence from about 480 and some have even said it goes back to the time of the Twelve Apostles.
In recent times the most common observance of Advent outside church circles has been the keeping of an advent calendar with one door being opened in the calendar, or an Advent candle with one section of the candle being burned, on each day in December leading up to Christmas Eve.
The Advent calendar, like many modern day aspects of the Christmas celebrations, is of German origin. In the early nineteenth century German Lutherans began to mark the days of Advent by marking walls or doors with a line of chalk each day. The later habit of hanging a devotional image every day led to the creation of the first known Advent Calendar in 1851. It's a handmade wooden calendar. As of the beginning of the 20th century, printed Advent calendars appeared, followed by Gerhard Lang's innovation of adding small doors in 1920. There were Bible Verses or pictures behind the doors. World War II terminated the success of this German tradition. The cardboard was rationed and it was forbidden to produce Calendars with pictures. The first printed specimen after the war were printed in 1946 by Sellmar-Verlag of Stuttgart. As of 1958 we know Advent Calendars filled with Chocolate. Today they are a global phenomenon, even seeing a boost in popularity in recent years, as one can nowadays buy all sorts of themed Advent calendars. But at their heart all of them retain the essence of counting down the days to Weihnachten that began with those simple chalk scratches.