War is an openly declared state of organized violent conflict, typified by extreme aggression, societal disruption, and high mortality.War generally involves two or more organized groups or parties (often, nations). The set of techniques used by a group to carry out war is known as Warfare.

Types of warfares :

Nuclear Warfare

Is a war in which nuclear weapons are the primary method of coercing the capitulation of the other side, as opposed to a supporting tactical or strategic role in a conventional conflict.

Civil War

Is a war where the forces in conflict belong to the same nation or political entity and are vying for control of or independence from that nation or political entity.

Asymmertic Warfare

Is a conflict between two populations of drastically different levels of military capability or size. Asymmetric conflicts often result in guerrilla tactics being used to overcome the sometimes vast gaps in technology and force size.

WHAT TO DO BEFORE

Some of the activities carried out under the authority of the War Precautions Act 1914 include:

• cancellation of commercial contracts with firms in enemy countries.
• interning of "enemy aliens"; and censorship of publications and letters.
• Go to underground place.
• Store sufficient stock like food, medical, batteries etc.
• Do not move outside in night.
• Wait for help.