Basic UNIX

UNIX was developed at AT&T’s Bell Laboratories after Bell Labs withdrew from a long-term collaboration with General Electrics (E) and MIT to create an operating system called MULTICS (Multiplexed Operating and Computing System) for G.E’s mainframe. In 1969, Bell Labs researchers created the first version of UNIX (then called UNICS, or Uniplexed Operating and Computing System) which has evolved over time to come to today’s Unix system.Here are few very popular UNIX flavors available today
Solaris Unix
Hewlett Packard HP-UX
Yellow Dog Linux (for apple system)
SCO OpenServer
Red Hat Enterprise Linux
SGI-IRIX
Fedora Core
SUSE Linux
Debian GNU
Mac OS X
FreeBSD
OpenBSD
KNOPPIX
NetBSD
OS/390 Unix
Plan 9Unix system is made up of different components that make Unix operating system such as a) Unix Kernelb) The Shellc) The File system, and the utilities.Unix Kernel is the lowest layer of the Unix system. The Kernel controls processes, input/output devices, file system operations, and manages memory.Shell is a command line interpreter used to interact between the users and operating system. Shell is used to administer and run system directly such as typing commands in the command line and executing them. There are many Shells available today amongst which three are very popular: the Bourne Shell (sh, bash), the C shell (csh), the Korn shell (ksh).Unix Utilities are important to enable system to run such as file system is one of the Unix utility that enables users to view, interact, and organize files and directories.