The GED, or General Education Development Test is a test that certifies the taker has attained U.S high-school level academic skills.
People who left high-school without graduating often find that that employers and post-secondary institutions will not accept them. Since adults typically cannot or will not return to high school, the GED allows them to demonstrate the skills they would have learned in high school. To pass the GED, the test taker must perform in the 40th percentile of high school seniors nationwide. For most purposes, a GED is the same as a high school diploma.