A collective biography or a group biography.
On skype, you are able to message people of your choice, call a single person or multiple people, and even video chat one or multiple people.
A book about someone's' life is a biography.
autobiography
jeevani
Multiple IP PBX can share multiple call processors with the use of standard interface.
A biography
main character.
Erin Hunter is actually three people-four now, I think. But there are certainly multiple authors of the Warriors and Seekers series.
A multiple number is a multiple when you times it by something. This is what you call a multiple.
A biography is used for telling about people's life.
To educate people about the person who the biography is about.and to tell people about someone important in the past.
Ben Chichoski does not have an official biography. You can read a bit about him on the Call of Duty wiki page.