This web site explains what BSD and Unix is very briefly and the way it’s fun to read. Also, it explains difference between Linux and BSD Unix.
I found out that there were so many S/W engineers who didn’t know abut the history of OSes, especially Unix. You would say it’s not necessary, but I’ll say YES.
Why? because most of the OS features you use are probably tested on Unix first in academic organizations and research centers. To understand commercial OSes like Windows and Mac OS X, it’s better to understand BSD and Unix.
Knowing BSD and Unix helps to understand philosophy of features and architectures of your probably favorite OS of choice.
Because it’s short, you will read it all before get bored.
Also, here is an explanation on differences between Linux and BSD additionally.
It’s not technical, but would serve for people who are in SI and IS business.