Question

What is the purpose of a dike?

Answer 1

The main purpose of a dike is protecting the land behind it from flooding.

Answer 2

The main purpose of a dike is protecting the land behind it from flooding, whereas a dams' purpose is to retain the water. 

Hope this answer helps! feel free to ask any additional questions :)

Also if you are good at Geometry, would you mind seeing if you could answer some of the questions on my profile?