What is the Reaping?

In The Hunger Games, a 2008 young adult novel by Suzanne Collins which was followed by two sequels (2009's Catching Fire and 2010's Mockingjay), "reaping" or "the reaping" was an annual civic event in which two youths would be randomly selected from each of the twelve districts of the nation of Panem to compete in the eponymous gladiator contest the Hunger Games.
The only detailed textual description given of a reaping in the book occurs in chapters one and two. According to it, the name of each youth between the ages of 12 and 18 within a district would be placed in a container and--during a public event--a representative from the Capitol would blindly select that of one male and one female. Each youth within a district would have their name placed in the container one time, buth could choose to have their names placed in the container additional times in exchange for allocations of foodstuffs. The two persons selected within a district during the reaping were known as "tributes."