Are daffodils and narcissus the same flowers?

The names "daffodil" and "narcissus" are interchangeable, but the name "jonquil" is used for Division 7 daffodils, characterized by very narrow, almost cylindrical, leaves and 1-5 (rarely up to 8) fragrant flowers per stem. Most other daffodils have flat leaves. All daffodils have some fragrance, and the jonquils and tazettas (Division 8) have the strongest. Most daffodils bloom within 4 to 6 weeks after the first appearance of foliage in the very early spring. Depending on location and cultivar, the blooming season can last from 8 weeks in northern climates to almost six months in the Lower South.

Answer taken from an article on Buzzle.com