Disasters are categorized into three Levels namely; minor, major and catastrophic disasters.

Minor:  The scope of a disaster is based on its sphere of influence. A major disaster impacts a wide region and causes hundreds of businesses to go into disaster recovery mode. A minor disaster impacts only a single organization and often a single application or storage system. Ironically, IT is under more pressure to recover more rapidly during a minor disaster than a major one.

Major: The President can declare a major disaster for any natural or man-made event – such as a hurricane, tornado, storm, high water, wind-driven water, tidal wave, tsunami, earthquake, volcanic eruption, landslide, mudslide, snowstorm, or drought, or, regardless of cause, fire, flood, or explosion – that he or she determines has caused damage of such severity that it is beyond the combined capabilities of state and local governments to respond.

Catastrophic disasters: The Philippines, China, Japan and Bangladesh are the targets of more natural disasters than anywhere else on Earth. They are the world's riskiest countries and are the most vulnerable to storms, floods, earthquakes, volcanoes, tsunamis, wildfires and landslides, among other calamities.