Advice: Worry about the differences later. Mac ~ Unix ~ Linux ¡ Linux vs Unix: https://www.linux.com/learn/answers/view/ 131-‐what-‐is-‐the-‐standard-‐difference-‐bw-‐linux-‐ and-‐unix ¡ How Unix is Mac OS? http://superuser.com/questions/ 49434/how-unix-is-mac-os-x ¡ Wikipedia: OS X http://en.wikipedia.org/wiki/OS_X