What we talk about when we talk about blazars?
  After the discovery of powerful relativistic jets from Narrow-Line Seyfert 1
Galaxies, and the understanding of their similarity with those of blazars, a
problem of terminology was born. The word blazar is today associated to BL Lac
Objects and Flat-Spectrum Radio Quasars, which are somehow different from
Narrow-Line Seyfert 1 Galaxies. Using the same word for all the three classes
of AGN could drive either toward some misunderstanding, or to the oversight of
some important characteristics. I review the main characteristics of these
sources, and finally I propose a new scheme of classification.
