The Newbery Medal is the most prestigious award for children's literature in the United States. It is awarded annually by the American Library Association (ALA) to the author of the most distinguished children's book published in the United States during the preceding year. The Newbery Medal was established in 1922 and is named after John Newbery, an 18th-century English publisher of children's books.
The Caldecott Medal is also an annual award given by the ALA, but it is for the most distinguished American picture book for children. The Caldecott Medal was established in 1937 and is named after Randolph Caldecott, a 19th-century English illustrator of children's books.
There is no such thing as a "gold" or "silver" Newbery award. There is only one Newbery Medal that is awarded each year.