After-school exercises-1

1. What is the relationship between Unix and Linux?
Linux is a set of free-to-use and freely-propagated Unix-like operating systems.
2. What is BSD? What do we usually say about FreeBSD, NetBSD, and BSD?
BSD (Berkeley software distribution, Berkeley Software suite) is a UNIX derivative system, "BSD" is not specifically a BSD derivative version, but a UNIX-like operating system of a branch of the general name.
3. UNIX licenses prohibit the use of UNIX source code in universities which year, followed by the emergence of two important UNIX version of the line, what is the difference?

4. AIX, Solaris, HP-UX, IRIX which companies have these UNIX developed? Which branch of Unix derivation are they based on (the two version lines in question 3rd)?

5. Please explain the concepts of GNU and GPL in the shortest words.

6. What are the changes in GPLv2 and GPLV1?

Linux is a free-to-use and free-to-propagate Unix-like operating system, a POSIX and Unix-based multiuser, multitasking, multi-threaded and multi-CPU operating system. It can run major UNIX tools software, applications, and network protocols. It supports 32-bit and 64-bit hardware. Linux inherits the design idea of Unix as the core of network, and is a stable multi-user network operating system.

Functionally speaking, almost no difference, Linux is to imitate the function of Unix developed, so called unix-like ...
From the performance point of view, although with the development of Linux has become more and more to replace the sense of Unix, but want to really replace is not so easy, because UNIX vendors are basically hardware and software co-development, UNIX system versatility is not high, mainly for specialized hardware dedicated design, So the performance and stability are extremely good, and Linux is a general-purpose system, most of the manufacturers do not produce their own hardware (only a handful of vendors like Redhat do so, so make money), so the biggest advantage of Linux is good compatibility, but this determines the performance can not play to the extreme ...
Commercially speaking, due to the performance differences above, resulting in two different business models, UNIX hardware and software sold together, and very expensive (except FreeBSD), and Linux only buy software, mostly free (like Radhat to go Unix road manufacturers, or a few); UNIX is suitable for large enterprises, while Linux is suitable for small and medium businesses and individuals ...

After-school exercises-1