Another question, is Linux the "only" open source OS that >exists out
there that people are using for schools, or are there other > >alternative
OSs that are in use?
Correct me if I am wrong but to me GNU/Linux is a name recognised by
users of different "open source" OSs. There is a great variety of open
source OSs, and their developers try to maintain the cohesion of "open
source" OSs by sharing the same common kernel of the OS. Linus Torvalds
is said to be the person who wrote the first kernel. That's why the
various distributions are called Linux.