GED stands for General Educational Development. It is a group of tests that covers five subjects: writing, reading, social studies, science and math. The GED is designed to measure if someone has mastered the skill sets of the subjects covered as required in a four-year high school education.
While there are some people who can wake up, decide they want a GED and earn the certificate the same day, most people need to prepare for the eight hour test. There are a variety of classes available, some provided online and others by training centers and educational institutions, such as community colleges. Training can last days, weeks or months depending on the program.
The requirements of GED testing can also impact the time it takes to earn a GED. Some states require you to take all tests in one sitting. Fatigue can become a factor in an eight hour test. Some states also dictate that a certain time period has to pass before you can retake a test.