GED stands for General Educational Development, General Education Diploma, or General Equivalency Development. The GED was created in 1942 to help veterans coming home from war apply to college or gain employment. Now it's used to give high school dropouts a second chance. It is not necessary for students who have earned a high school diploma.
The GED is used to demonstrate a student knows as much as a high school graduate. In the U.S., students must be age 16 and not currently enrolled in high school. It costs about $100 to $150, depending on the state. The GED is about 7 hours long. It tests math (including basic math, geometry, algebra, graphs and functions), language arts (including reading, grammar, language, and a written essay), social studies (including reading and analyzing historical events and using numbers and graphs for meaning), and science (including the meaning of science, experiments, and using numbers and graphs).