What makes Ubuntu so popular and on the rise

[OOzy Pal]

Dears,

I was surprised when people stared to recommend Ubuntu to me. I was like:

"hmmmm, Ubuntu!!!!! what is Ubuntu???"

Even though, I was using Mandrake (Mandriva) but I heard about SuSE,
Red Hat, Fedora, Slackware and Caledra.

I have no intention behind this question so please don't misunderstand
me. It is just pure curiosity. Moreover, I am planning to switch from
Mandriva to Ubuntu and I would like to see the side the people are
seeing in Ubuntu which I am not.

--
OOzy