There are two camps of operating systems, one is based on Microsoft Windows NT and the other is derived from UNIX.
Linux, Mac OS X, Android, iOS, Chrome OS and even firmware on routers are all in the same family, based on the original UNIX operating system, collectively known as the UNIX-like operating system.
The Unix system was developed by AT&T Bell LABS in the 1960s. The Unix philosophy is to focus on one thing to create small, elegant tools and make them perfect. For example, on a Linux terminal, you can use pipe characters to combine several tools to accomplish a complex task. On Unix systems, everything is a file, including hardware devices and special files.
The descendants of Unix
Up to now, Unix has been more than 40 years of history, there are many descendants. In short, Unix has evolved along two lines.
The academic branch
A branch developed in academia. Berkeley Software Distribution (BSD) is an open source UNIX-like operating system. BSD has spawned FreeBSD, NetBSD, and OpenBSD. NeXTStep was also built on BSD, apple’s OS X was built on NeXTStep, and iOS was built on OS X.
MINIX is a UNIX-like operating system for teaching. First MINIX inspired, college Linux developed the Linux operating system. The Linux operating system we’re talking about today is actually GNU/Linux, but why we add the word ‘GNU’ is another topic. GNU/Linux consists of the Linux kernel and many GNU tools. GNU/Linux did not grow directly out of BSD, but it was based on Unix, and it came out of campus, in the academic branch after all. Today’s common Android, Chrome OS and embedded operating systems are all based on the Linux operating system.
Commercial branch
AT&T UNIX, SCO UnixWare and Sun Microsystems Solaris are commercial operating systems developed by large companies. Commercial operating systems are not often touched, so I won’t go into that.
The Unix family tree below
DOS and Windows NT
With the popularity of the IBM PERSONAL PC, the Microsoft DOS operating system became popular on personal computers. DOS is an operating system entirely separate from Unix, as can be seen from its use of backslashes to denote file and directory separators. Unix used forward slashes to split file directories in the 1970s, but DOS, which became popular on personal computers in the 1980s, did not support file directories. DOS used forward slashes to represent conversion characters, so much so that it was later chosen to represent directory separators with backslashes when DOS2.0 supported directories. Windows 3.1, Windows 95, Windows 98, and Windows ME were all DOS, and then Microsoft developed the next generation of operating system, Windows NT (Windows New Technology), Windows XP is its masterpiece. After this, Windows 7, Windows 8, Windows RT, Windows Phone 8, Windows Server are Windows NT kernels. Windows NT is also not a UNIX-like operating system. In order to be compatible with previous DOS systems and Windows software, Windows NT uses some DOS designs, such as disk characters, directory backslash, forward slash command switch, etc.
Reference: https://blog.csdn.net/bdss58/article/details/77775770