The flag of the United States consists of thirteen horizontal striped alternating red and white, starting and ending with red. In the top right, there is a blue canton with fifty white five-pointed stars. This canton alone is the United States Jack.
The thirteen stripes stand for the original Thirteen Colonies. Each of the stars stands for a US State; there are fifty total. The official ratio of the US flag is 19:10, but most commercially-available flags are in other rations, such as 2:3.