Most operating systems can be grouped into two different families.
Aside from Microsoft’s Windows NT-based operating systems, nearly
everything else traces its heritage back to Unix.
Linux, Mac OS X, Android, iOS, Chrome OS, Orbis OS used on the
PlayStation 4, whatever firmware is running on your router — all of
these operating systems are often called “Unix-like” operating systems.
Unix’s Design Lives On Today.
Unix was developed in AT&T’s Bell Labs back in the mid-to-late
1960′s. The initial release of Unix had some important design attributes
that live on today.One is the “Unix philosophy” of creating small, modular utilities
that do one thing and do them well. If you’re familiar with using a Linux terminal, this should be familiar to you — the system offers a
number of utilities that can be combined in different ways through pipes and other features
to perform more complex tasks. Even graphical programs are likely
calling simpler utilities in the background to do the heavy lifting.
This also makes it easy to create shell scripts, stringing together simple tools to do complicated things.
Unix also had a single file system that programs use to communicate with each other. This is why “everything is a file” on Linux
– including hardware devices and special files that provide system
information or other data. It’s also why only Windows has drive letters,
which it inherited from DOS — on other operating systems, every file on
the system is part of a single directory hierarchy.