UNIX is a certification for operating systems.
· Linux is an operating system kernel.
· The UNIX standard evolved from the original UNIX system developed at Bell Labs. After Unix System V, it ceased to be developed as a single operating system, and was instead developed by various competing companies, such as Solaris (from Sun Microsystems), AIX (from IBM), HP-UX (from Hewlett-Packard), and IRIX (from Silicon Graphics). UNIX is a specification for baseline interoperability between these systems, even though there are many major architectural differences between them.
· Linux has never been certified as being a version of UNIX, so it is described as being "Unix-like.". In 1985, Richard Stallman created the Free Software Foundation and developed the GNU General Public License (GNU GPL), in order to spread software freely. Many of the programs required in an OS (such as libraries, compilers, text editors, a UNIX shell, and a windowing system) were completed by the early 1990s, but few elements such as device drivers, daemons, and the kernel were incomplete. In 1991, Linus Torvalds began to work on MINIX, a Unix-like OS, whose code was freely available under GNU GPL project. Then he developed the first LINUX kernel and released it on 17 September 1991, for the Intel x86 PC systems. This kernel included various system utilities and libraries from the GNU project to create a usable operating system. All underlying source code can be freely modified and used.
· Initially Unix was a command based OS, but later a GUI, popularly known as X Window was created for UNIX.
· Linux typically provides two GUIs, KDE and Gnome. But Linux GUI is optional.
· In case of Unix, user has to wait for a while, to get the proper bug fixing patch.
· In case of Linux, threat detection and solution is very fast, as Linux is mainly community driven and whenever any Linux user post s any kind of threat, several developers start working on it from different parts of the world.
