What is the expansion of Nokia N series, E series, X series and C series phones

We all are familiar with the Nokia mobile phones. The new generation Nokia phones comes in a variety of series Nokia N series, Nokia E series etc. The recently to be launched Nokia series include C- Series and X - series.

Here is the expansion of those abbreviations
E-series - Enterprise series
N - series - Entertainment series (N=En)
X - series - Xpress Music
C- series - Classic series