Delta Force goes by many official and unofficial names. It is most commonly referred to as "The Unit," but those in the inside call it CAG (Combat Applications Group). Whatever you call it, no one ever speaks of Delta Force officially and such, no one really knows exactly what instructors are looking for in future operators.
"It's not always the best guy that makes it," said former Delta Force operator Pat Savidge in this Military Channel video. "It's the right guy."
Delta Force operators are the toughest of the tough. The group is made up of elite soldiers and special forces troops from all branches of service, including the National Guard and Coast Guard.
This video shows what it takes to try out for Delta Force: