UNICEF
1. the United Nations International Children's Fund
2. United Nations International Children's Fund
(What is the full form of UNICEF? Do we have to add 'the' or not? Thank you. And let me know a website which contains the explanation about the organization in simple English for children?)
This is about as simple an explanation as there is. If you want further information let me know.
http://wiki.answers.com/Q/What_is_UNICEF
The full form of UNICEF is the United Nations International Children's Fund. So, including "the" in the name is technically correct.
When it comes to finding a website that explains UNICEF to children in simple English, a good resource is the official UNICEF website for children: UNICEF Kid Power (https://www.unicefusa.org/kid-power).
UNICEF Kid Power is a fun and interactive website that provides information about UNICEF's work in a way that is easier for children to understand. It includes games, videos, and activities that teach children about the organization's mission, projects, and the impact it has on children around the world.