Psychiatric and substance abuse hospitals employed only 3,210 security guards, according to the BLS, less than 8 percent of all hospital guards. However, they were the best paid in the industry, earning an average of $35,000, or $16.83 an hour.
So the basic differences between Cavalry, Artillery and Infantry are as follows. 1  Infantry: Infantry refers to the soldiers on foot. 2  Cavalry: It generally means mounted soldiers. 3  Artillery: It uses large and long ranged weapons.
Doctrine describes how a force operates, or how an army fights. Strategy describes the overall approach to achieving the goal; tactics describes the specifics, e.g., when an army is in contact with the enemy. Doctrine describes in both cases the principles as to how the fight will be waged.