What is WTO? When was it set up? How does it function?

World Trade Organisation is referred as WTO. As the name suggests the main role of the organisation is to set rules for global trade. It was the successor of GATT in the year 1995. It has 164 member countries in all. All decisions are taken unanimously by ambassadors or delegates. The developing countries often complain of non-transparent procedures and WTO being pushed around by big powers.