Dragon Ball Z is both anime and manga. The anime was adapted from the manga and they share the same story and characters, but presented in different mediums.
Sorry to disappoint you. The Dragon Ball Z manga is not ongoing. It had its own definitive ending, but its popularity continues through various forms of media and merchandise.
Definitely! Dragon Ball Z manga has gained massive popularity worldwide for its exciting storyline, memorable characters, and action-packed scenes. It's become a cultural phenomenon in many countries.
It's hard to give an exact count because there have been various reprints and special editions. But generally, there are quite a few volumes that make up the Dragon Ball Z manga series.