The President of the United States is the Commander in Chief, who is responsible for all final decisions. The Secretary of the Department of Defense (DoD) has control over the military and each branch - except the Coast Guard, which is under the Dept. of Homeland Security. With over 2 million civilian and military employees, the DoD is the world's largest "company."
After enlistment, new recruits undergo basic training (also known as "boot camp" in the Marine Corps, Navy and Coast Guard), followed by schooling in their primary Military Occupational Specialty (MOS), rating and Air Force Specialty Code (AFSC) at any of the numerous training facilities around the United States. Each branch conducts basic training differently. The Marine Corps send all non-infantry MOS's to an infantry skills course known as Marine Combat Training prior to their technical schools. Air Force Basic Military Training graduates attend Technical Training and are awarded their Air Force Specialty Code (AFSC) at the apprentice (3) skill level. All Army recruits undergo Basic Combat Training (BCT), followed by Advanced Individual Training (AIT), with the exceptions of cavalry scouts, infantry, armor, combat engineers and military police recruits who go to One Station Unit Training (OSUT), which combines BCT and AIT. The Navy sends its recruits to Recruit Training and then to "A" schools to earn a rating. The Coast Guard's recruits attend basic training and follow with an "A" school to earn a rating.
As of 2017, the U.S. spends about US$610 billion annually to fund its military forces and Overseas Contingency Operations. Put together, the U.S. constitutes roughly 40 percent of the world's military expenditures. The U.S. Armed Forces has significant capabilities in both defense and power projection due to its large budget, resulting in advanced and powerful technologies which enables a widespread deployment of the force around the world, including around 800 military bases outside the United States. The U.S. Air Force is the world's largest air force, the U.S. Navy is the world's largest navy by tonnage, and the U.S. Navy and the U.S. Marine Corps combined are the world's second largest air arm. In terms of size, the U.S. Coast Guard is the world's 12th largest naval force. 
Don’t let the PC section of the test throw you for a loop. Unlike the individual multiple choice questions in other sections, here you will need to read a paragraph and answer several questions in a row based on that one paragraph. The people who designed this section of the exam really knew how to make sure you are able to read detailed (and often boring) documents, remember the details of what you read, understand why they’re important, and be able to pick out the key concepts they illustrate. When you read each paragraph, it’s helpful to know the kinds of questions you’ll be asked at the end. There are basically four kinds of questions to test your comprehension:
The ASVAB test is administered to potential military recruits to help determine which branch of service and which military jobs they will be best suited for. It is not a test of intelligence and is administered only in English. The test consists of nine subjects: General Science, Arithmetic Reasoning, Word Knowledge, Paragraph Comprehension, Mathematics Knowledge, Electronics Information, Auto and Shop Information, Mechanical Comprehension, and Assembling Objects.
SOC is a consortium of more than 1550 colleges and universities that provide educational opportunities for servicemembers and their families. It is co-sponsored by the American Association of State Colleges and Universities (AASCU) and the American Association of Community Colleges (AACC) and managed for the DoD by the Defense Activity for Non-Traditional Education Support (DANTES). Course work can be done on campus, at military installations and armories, and at a distance by computer or correspondence. Associate, bachelor, and graduate-level degree programs are available. Special curriculum areas include SOCAD (Army), SOCNAV (Navy), SOCMAR (Marines), and SOCGuard (Army National Guard). In addition, SOC operates ConAP (Concurrent Admissions Program) to increase college enrollment of Army enlistees (Army and Army Reserves). ConAP allows you to enlist in the Army at the same time as you apply for college. DANTES also operates its own Distance Learning Program. For more information, contact: