This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.
An operating system (OS) is software on a computer that manages the way different programs use its hardware, and regulates the ways that a user controls the computer. There are two types of Operating Systems. With a command-line operating system as an example DOS, you type a text command and the computer responds according to that command. When it comes to graphical user interface (GUI) operating system such as Windows, you interact with the computer through a graphical interface with pictures and buttons by using the mouse and keyboard. When you consider UNIX, you have in general the option of using either command-lines or GUIs. When we are talking about command-lines, it's more control and flexible. And GUI is easier to use for the users.
UNIX operating systems are widely used in both servers and workstations. The UNIX environment and the client-server program model were essential elements in the development of the Internet and reshaping of computing as centered in networks rather than in individual computers, which is a layered operating system
Normally Windows operating system has a Graphical User Interface but UNIX has basically command line interface, which are two classes of operating systems.
And they have a competitive history and future. UNIX has been in use for more than three decades. Originally it rose from the ashes of a failed attempt in the early 1960s to develop a reliable timesharing operating system. A few survivors from Bell Labs did not give up and developed a system that provides a work environment described as "of unusual simplicity, power, and elegance".
Since the 1980's UNIX's main competitor Windows has gained popularity due to the increasing power of micro-computers with Intel-compatible processors. Windows, at the time, was the only major OS designed for this type of processors. In recent years, however, a new version of UNIX called Linux, also specifically developed for micro-computers, has emerged. It can be obtained for free and is therefore a lucrative choice for individuals and businesses.
Most important thing when it comes to operating system is security. There are three basic principles for protecting information.
Confidentiality-Information must be kept from those who do not have a need to know.
Availability-Information must be available to those who need access to it.
Integrity-Information must be free from unauthorized changes or contamination.
When the user understands the value of what they are protecting, they can determine the appropriate level of resources to spend securing those assets in a meaningful and sensible manner. Following are the assets to identify when it comes to security.
Hardware - The physical components of the computer system have value. If the system is located in an easily accessible place without any physical security in the form of locked doors, then it can be stolen. If someone can physically touch the computer system, he or she can potentially access all of the information it contains because the system can be booted off of alternative file systems bypassing the primary operating system. An attacker could also insert network monitoring software to capture all the information passed over the network, a key logger, and many other means of assault. An attacker could also simply take the computer and remove the hard drive to gain access to the information the system holds.
Network connection - Network connection is an extremely valuable resource. Attackers can use bandwidth or network capacity in various kinds of attacks against other systems. They also can use the network connection, effectively using the user's identity on the Internet, which to anyone on the outside would look like the attacks were coming from user's location.
Services - If the user uses his computer to share information with any other users either in his department at works or with his family at home, it will be important to him that his system continues to provide those services without interruption. If user has a home-based business that relies on his Web server for marketing his product to customers, for example, he need to have the Web service running at all times, or he'll lose business.
Data - Everything that user uses his computer for is stored in the system: User's e-mail, address lists, personal files, and other things that user has personally created or modified. Any numbers of confidential documents are located in his computer. Think about how difficult it would be to recreate everything located on his hard drive if he had to. There is also the threat that someone can use that information to assume his identity, accessing his financial-planning program and e-mails.
There are three primary types of accounts on a UNIX system: the root user account, system accounts, and user accounts. Almost all accounts fall into one of those categories.
User Accounts - User accounts provide interactive access to the system for users and groups of users. General users are typically assigned to these accounts and usually have limited access to critical system files and directories. Generally if user wants to use eight characters or fewer in an account name, but this is no longer a requirement for all UNIX systems. For interoperability with other UNIX systems and services, however, user will most likely want to restrict his account names to eight characters or fewer. An account name is the same as a username.
System Accounts - System accounts are those needed for the operation of system-specific components. System accounts are generally provided by the operating system during installation or by a software manufacturer. They generally assist in the running of services or programs that the users require.
There are many different types of system accounts, and some of them may not exist on your UNIX system. These accounts are usually needed for some specific function on your system, and any modifications to them could adversely affect the system. Do not modify them unless you have done your research on their functionality and have tested the system with any changes.
Root Accounts - The root account's user has complete and unfettered control of the system, to the point that he can run commands to completely destroy the system. The root user also called as root can do absolutely anything on the system, with no restrictions on files that can be accessed, removed, and modified. The UNIX methodology assumes that root users know what they want to do, so if they issue a command that will completely destroy the system, UNIX allows it. If you are used to working with Microsoft Windows, its administrator account is most like Unix's root account, except that Windows generally tries to protect itself from you. If you try to format the disk that the operating system is on, Windows prevents you from doing so, but Unix accepts the command and starts formatting with no regard to self-destruction. This basic tenet is why people generally use root for only the most important tasks, and then use it only for the time required and very cautiously.
Then one of the most important topics is the file system. A file system is a logical collection of files on a partition or disk. A partition is a container for information and can span an entire hard drive if desired. File system is a component of UNIX that enables the user to view, organize, secure, and interact with files and directories that are located on storage devices.
Everything in UNIX is considered to be a file, including physical devices such as DVD-ROMs, USB devices, floppy drives, and so forth. This use of files allows UNIX to be consistent in its treatment of resources and gives the user a consistent mechanism of interaction with the system. It's easy to understand, then, why file systems are an integral part of a UNIX operating system.
There are different types of file systems within UNIX are Disk-oriented, Network-oriented Special also mention as Virtual.
Disk-oriented file system - Physically accessible file systems residing on a hard drive, CD-ROM, DVD ROM, USB drive, or other device.
Network-oriented file system - A file system accessed from a remote location. These are usually disk-oriented on the server side, and the clients access the data remotely over the network. Examples include Network File System (NFS), Samba (SMB/CIFS), AFP (Apple Filing Protocol).
Special, or virtual, file system-A file system that typically doesn't physically reside on disk, such as the TMPFS (temporary file system), PROCFS (Process File System), and LOOPBACKFS (the Loopback File System).
Advantages of UNIX
- Unix is more flexible and can be installed on many different types of machines, including main-frame computers, supercomputers and micro-computers.
- Unix is more stable and does not go down as often as Windows does, therefore requires less administration and maintenance.
- Unix has a great built-in security and permissions features than Windows.
- Unix possesses much greater processing power than Windows.
- Unix is the leader in serving the Web. About 90% of the Internet relies on UNIX operating systems running Apache, the world's most widely used Web server.
- Software upgrades from Microsoft often require the user to purchase new or more hardware or prerequisite software. That is not the case with UNIX.
- The mostly free or inexpensive open-source operating systems, such as Linux and BSD, with their flexibility and control, are very attractive to (aspiring) computer wizards. Many of the smartest programmers are developing state-of-the-art software free of charge for the fast growing "open-source movement".
- Unix also inspires novel approaches to software design, such as solving problems by interconnecting simpler tools instead of creating large monolithic application programs.
Remember, no single type of operating system can offer universal answers to all your computing needs. It is about having choices and making educated decisions.