I am new to this operating system.Please tell me how it works and how it is different from windows or Dos platforms.

please use the search function, as this question has been answered many many times.
thanks.

Firstly,Operating system(OS)is the system and a basic software that co-ordinate and controls the computer hardware,softwaresand also mages file of a computer .They can be classified in thier mode of operation which are text based(ms-dos,unix),graphical based(window 98,2003.NT.XP)and both the text and the graphicbased(linux)It can also be classified in thier operational capability.Which are single tasking and multitasking.The single performs its operation one step before another ,it can not perform them at once.The multi tasking,due to the speed of the micro processor which can be in millionth or in billion times per second it executes it job as though it is doing it at the same time.This is done by time slicing.Functions,It manages hardware error,Manages the file and also controls the peripheral unit which are the monitor,keyboard,printer,system unit in which we find the CPU,RAM,ROM,etc.
Also Dos meaning disk operating system is an old form of OS,it is actually not operational like the Ms-Dos which is the improved version.All this was manufatured by microsoft co-orperation.

Jargon File

Unix /yoo'niks/ n. [In the authors' words, "A weak pun on Multics";
very early on it was `UNICS'] (also `UNIX') An interactive time-sharing
system invented in 1969 by Ken Thompson after Bell Labs left the Multics
project, originally so he could play games on his scavenged PDP-7.
Dennis Ritchie, the inventor of C, is considered a co-author of the
system. The turning point in Unix's history came when it was
reimplemented almost entirely in C during 1972-1974, making it the first
source-portable OS. Unix subsequently underwent mutations and expansions
at the hands of many different people, resulting in a uniquely flexible
and developer-friendly environment. By 1991, Unix had become the most
widely used multiuser general-purpose operating system in the world -
and since 1996 the variant called Linux has been at the cutting edge
of the open source movement. Many people consider the success of Unix
the most important victory yet of hackerdom over industry opposition
(but see Unix weenie and Unix conspiracy for an opposing point of
view). See Version 7, BSD, Linux.

Some people are confused over whether this word is appropriately
`UNIX' or `Unix'; both forms are common, and used interchangeably.
Dennis Ritchie says that the `UNIX' spelling originally happened in
CACM's 1974 paper "The UNIX Time-Sharing System" because "we had a new
typesetter and troff had just been invented and we were intoxicated by
being able to produce small caps." Later, dmr tried to get the spelling
changed to `Unix' in a couple of Bell Labs papers, on the grounds that
the word is not acronymic. He failed, and eventually (his words) "wimped
out" on the issue. So, while the trademark today is `UNIX', both
capitalizations are grounded in ancient usage; the Jargon File uses
`Unix' in deference to dmr's wishes.

---------------------------------

The Free On-line Dictionary of Computing

<operating system> /yoo'niks/ (Or "UNIX", in the authors'
words, "A weak pun on Multics") Plural "Unices". An
interactive time-sharing operating system invented in 1969
by Ken Thompson after Bell Labs left the Multics
project, originally so he could play games on his scavenged
PDP-7. Dennis Ritchie, the inventor of C, is considered
a co-author of the system.

The turning point in Unix's history came when it was
reimplemented almost entirely in C during 1972 - 1974, making
it the first source-portable OS. Unix subsequently
underwent mutations and expansions at the hands of many
different people, resulting in a uniquely flexible and
developer-friendly environment.

By 1991, Unix had become the most widely used multi-user
general-purpose operating system in the world. Many people
consider this the most important victory yet of hackerdom over
industry opposition (but see Unix weenie and Unix
conspiracy for an opposing point of view).

Unix is now offered by many manufacturers and is the subject
of an international standardisation effort [called?].
Unix-like operating systems include AIX, A/UX, BSD,
Debian, FreeBSD, GNU, HP-UX, Linux, NetBSD,
NEXTSTEP, OpenBSD, OPENSTEP, OSF, POSIX, RISCiX,
Solaris, SunOS, System V, Ultrix, USG Unix, Version
7, Xenix.

"Unix" or "UNIX"? Both seem roughly equally popular, perhaps
with a historical bias toward the latter. "UNIX" is a
registered trademark of The Open Group, however, since it is
a name and not an acronym, "Unix" has been adopted in this
dictionary except where a larger name includes it in upper
case. Since the OS is case-sensitive and exists in many
different versions, it is fitting that its name should reflect
this.

The UNIX Reference Desk
(http://www.geek-girl.com/unix.html).

Read the link here...

Read this if you are serious about being a Unix Admin...