Shocks are the general reaction of the body to the sudden circulatory collapse from either a decrease in the circulating volume of blood or a massive vasodilation of the veins which enables the blood to be distributed. It may either be a result from massive bleeding, a decrease in the capacity of the heart to pump blood or inability of the blood to be circulated.
Shock is the body's reaction to decreased blood and oxygen supply throughout the body. This results to blood pressure becoming too low and is mostly caused by bleeding, dehydration, heart failure and infection. Look here for more information: http://www.ask.com/wiki/Shock_(circulatory).
Shock is the bodies reaction to trauma but there are different types of shock. Someone can go into a Anaphylactic shock which is caused by a allergic reaction to something. There is also a Septic shock, a Cardiogenic shock and a Neurogenic shock.