There are more than 100 million orphans worldwide.
Major causes include poverty, disease, war, famine and HIV/AIDS.
The United Nations estimates the December 26, 2004, tsunami has left 1.5 million children homeless, most of whom may be orphaned.
Aid officials estimate that as a result of the December 26, 2004, tsunami more than 35,000 children have been orphaned in Indonesia and another 300 in Thailand, while in Sri Lanka, officials are attempting to count and identify children among the 800,000 people who have been displaced.
Adoption experts say the best thing people can do to help orphans is to donate money to causes that directly help the children.
