It's earned by successfully completing a standardized test covering subjects typically taught in high school, such as:
* Reading: Comprehension and interpretation of written text.
* Writing: Composition and grammar skills.
* Mathematics: Arithmetic, algebra, and geometry.
* Science: Basic concepts in biology, chemistry, and physics.
* Social Studies: History, civics, and economics. (This might be combined with other subjects on some tests).
The specific requirements and testing process vary slightly from state to state, but the overall goal remains the same: to certify that someone has mastered the fundamental knowledge and skills generally associated with a high school education. The GED is the most widely known example of a high school equivalency credential, but other tests and programs exist.