What's the biggest waterfall in the world?

This depends on what is meant by 'biggest'. If 'biggest' refers to 'largest', then the largest waterfall is Victoria Falls on the border of Zambia and Zimbabwe, with a flow rate of 1088 m³/s (38,430 cu ft/s) and a height of 108 metres (360 feet).

If 'biggest' means 'tallest', the tallest waterfall is Angel Falls in Venezuela, measuring 979 metres (3,212 ft) in length.

If 'biggest' means 'widest', the widest waterfall is the Iguazu Falls on the border of Brazil and Argentina, with some falls that have a width of over 150 metres (492 feet).

Some famous waterfalls, yet not the largest, include Niagara Falls, split between Canada and the U.S., the most powerful in North America. Niagara has an average flow rate of 64,750 cu ft/s (1,833 m3/s). Also, the Yosemite Falls of Yosemite National Park are the world's fourth tallest at 2,425 ft (739 m) tall. :) :)

The highest is Angel Falls.

But in terms of biggest, meaning most amount of water per minute, it has to be Iguazu Falls. (Although Some people claim Victoria Falls. Victoria Falls is some 50 meters narrower, but during a wet season the water discharged was measured at slightly more than Iguazu Falls.)

Angel falls