Navy SEALs work for the United States Navy in the special operations force called the Naval Special Warfare (NSW). The NSW makes up only 1% of the United States Navy. SEAL stands for Sea, Air and Land. Navy SEALs are trained in air and land tactics, but begin and end their operations in the environment of the sea.

Primary Navy SEALs training is concerned mainly with special reconnaissance (SR) and direct action (DA) as these are considered by the United States Navy NSW to be basic SEAL skills. SR missions are conducted by NSW as a means of preparing military troops for what to expect in enemy territory; Navy SEALs covertly survey enemy operations and weaponry. They bring intelligence back to the NSW. DA involves direct confrontation strategies such as trained snipers ready to protect other United States military personnel. Navy SEALs select the right weapons for each job such as handguns, rifles, grenade launchers, shot guns, or sniper rifles.

The six months basic Navy SEALs training is called Basic Underwater Demolition/SEAL (BUD/S) and is both physically and mentally demanding. A three week parachute course and advanced training lasting 15 weeks is also mandatory for Navy SEALs to earn the "Trident" pin that signifies a SEAL. After the first SEAL training phase is completed, prospective Navy SEALs are given a sheet of paper called a "Dream Sheet" that they use to voice their choice of either San Diego, California, or Virginia Beach, Virginia. Two of the four groups that deploy Navy SEALs are in San Diego and the other two are in Virginia Beach. The total number of Navy SEALs add up to more than 2,450 and there are also 325 reserve Navy SEALs.

Special operations forces are small, focused units. Navy SEALs are expected to expertly handle equipment and strategic tactics in SEALs missions around the world. Navy SEALs are trained to attack their targets unexpectedly, day or night, either by parachute or by submarine.

Special Warfare Combatant Craft Crewmen (SWCC)are not the same as Navy SEALs even though both are part of the NSW. SWCC undergo training similar to Navy SEALs, but their focus is on the maintenance and operation of watercraft and weapons. The SWCC aid and support SEALs in shallow water areas. Both Navy SEALs and SWCC must have excellent fitness, intelligence, motivation and be able to respond accurately in stressful situations.

Both prospective SWCC and prospective Navy SEALs must have 20/20 vision, or at least vision that is considered correctable to 20/20 by laser eye surgery. Both SWCC and Navy SEALs must have received at least the minimum allowable scores on the Armed Services Vocational Aptitude Battery (ASVAB). The ASVAB tests ten subjects and the scores achieved in each area indicate eligibility for basic Navy SEALs training or basic SWCC training. Prospective SWCC usually require high scores in Arithmetic Knowledge (AK), Word Knowledge (WK) and Mechanical Comprehension (MC). Prospective Navy SEALs often need to score high in General Science (GS), Electronics Information (EI) and Mechanical Comprehension (MC).