What is the difference between duodenal atresia and duodenal stenosis?

What is the difference between duodenal atresia and duodenal stenosis?

Duodenal atresia and duodenal stenosis are both congenital blockages of the small intestine.

Babies with duodenal atresia have a complete closure in the first part of their duodenum. Babies with duodenal stenosis have an unusually narrow duodenum.