In the chaos, tragedy, and trauma that follow a major disaster, many people and governments are moved to give aid to the victims. Aid is split into two types, humanitarian and reconstruction. Humanitarian, or relief aid, covers immediate human needs: rescue, food, clothing, water, medicines, temporary shelter. Reconstruction aid is money and equipment for long-term projects and recovery, such as rebuilding roads, bridges, railways, and providing permanent housing. Relief money arrives quickly; reconstruction money is often delayed, or sometimes never arrives.
Donations from governments follow a particular process in response to a disaster. First, governments will announce a pledge verbally through a spokesperson. This is a general nonbinding vow of assistance, including both relief and reconstruction aid. It is a declaration of intent. Next is the commitment stage, in which a government signs a legally binding contract listing the actual amount of money that will be donated. Finally, governments filter their cash through to the scene of the disaster in three ways: giving the money to the UN, to NGOs working on the ground, or directly to the affected country's government. For some large disasters, such as 2004's tsunami, the World Bank acts as a collecting agency for various country's donations.
That all takes time. Therefore relief agencies like the World Food Programme have money and supplies that are ready to be released and distributed worldwide within hours of a disaster. When the relief money arrives later, it is used to refill these emergency stocks.
—David A. O'Connor