"Black projects" refer to highly classified government or military programs that are not publicly acknowledged. These projects often involve advanced technology, research, or operations that are kept secret for national security reasons. Examples can include experimental aircraft, weapons systems, or intelligence operations that are not disclosed to the public or even to many government officials. Due to their secretive nature, black projects can sometimes lead to speculation and conspiracy theories. They are typically funded through untraceable budgets, making it difficult to track their costs or objectives. The term is often associated with organizations like the U.S. Department of Defense and NASA, which may engage in such covert activities.