What is the united nations and how does it work ? (Hindi)

We all heard about United Nations and we all know this is one of the most important organisation on the planet earth. But what is the united nations and how does it work. United Nations play a major role in maintaining world peace but is this the only work they do ? and where they are witch country own this organisation. Is there any special status for some countries or all the countries are same in this organisation. When and how it formed and who operate this kind of massive organisation and which countries are member of this organisation. Everything about it.