What is a delta and how is it produced?
A delta is a piece of fertile land located at the edge of a river. They are always triangular in form, hence its name best describes (delta-Greek letter shaped like a triangle).
How it forms? Simple. The end of a river is always the stock of washed away sediments, in which of them are rich in minerals, which can be found in runaways of glaciers. As the river flows, it slowly erodes one part of land on the river's mouth, thus a delta has several branches due to erosion.
The delta has greatly helped agriculture since the antiquity times. Taking for instance the Nile Delta. The world's once greatest civilizations flourished in the delta, wherein the ancient Egyptians raised wheat to supplement food supply.
I hope you were enlightened with this.