Computers for Organisations

Computers for Organisations:

Some computers handle the needs of many users at the same time. These powerful systems are most often used by organizations, such as businesses or schools, and are commonly found at the heart of the organization‘s network. . Generally, each user interacts with the centralized computer through his or her own devrce (generally desktop computer), freeing people from having to wait their turn at a Single

keyboard and monitor. The largest organizational computers support thousands 0f individual users at the same time, from thousands of miles away.

The four primary types of computers in this category are

Network Servers

Mainframe Computers 

Minicomputers

Supercomputers 

Network Servers:

Today, most organisations' networks are based on personal computers. Individual users have their own desktop computers, which are connected to one or more centralised computers, called network servers. A network server is usually a powerful personal computer with special software and equipment that enable it to function as the primary computer in the network

PC-based networks and sewers offer companies a great deal of flexibility. A PC-based server gives users flexibility to do different kinds of tasks. For example, some users may rely on the server for e-mail access, some may use it to perform accounting tasks, and others may use it to perform word-processing or database-management jobs. The server can support these processes, and many others, while storing information and programs for many people to use.

Mainframe Computers:

Mainframe computers are used in large organisations such as insurance companies and banks, where many peOple frequently need to use the same data. in a traditional mainframe environment, each user accesses the mainframe's resources

through a device called a terminal. There are two kinds of terminals. A dumb terminal does not process or store data; it is simply an input/output (l/O) device that functions as a window  into a computer located somewhere else. An intelligent
terminal can perform some processing operations, but it I usually does not have any storage. In some mainframe
environments, however, workers can use a standard personal  Mainframe computer to access the mainframe. Computer

Mainframes are large, powerful systems  The largest mainframes can handle the processing needs of thousands of users at any given moment. But what these systems offer in power, they lack in flexibility. Most mainframe systems are designed to handle only a specific set of tasks. In your state's Department of Motor Vehicles, for example, a mainframe system is probably devoted to storing information about drivers, vehicles, and driver's licenses, but little or nothing else. By limiting the number of tasks the system must perform, ' administrators preserve as much power as possible for required operations.

You may have interacted with a mainframe system without even

knowing it. For example, if you have ever visited an airline’s :Web site to reserve a seat on a flight, you probably conducted a transactions with a mainframe computer

Minicomputers:

First released in the 19603, minicomputers got their name because of their small size compared to other computers of the day. The capabilities of a minicomputer are somewhere between those of mainframes and personal computers. For this reason, minicomputers are often called midrange computers like mainframes, minicomputers can handle much more input and output than personal computers can. 

Supercomputers:

supercomputers are the most powerful computers made, and physically they are some of the largest . These systems can process huge amounts of data, and the fastest supercomputers can perform more than one trillion calculations per second. Supercomputers can house thousands of processors and ideal for handaling large and highly complex problems that 

Computer for individual users

Computers for Individual Users

Most computers are meant to be used by only one person at a time. Such computers are often

shared by several people (such as those 1n our centre' s computer lab), but only one user can work with the machine at any given moment.

The six primary types of computers in this category are
* Desktop computers
* Workstations
* Notebook computers
* Tablet computers
* Handheld computers
* Smart phones

Introduction to Computers

Desktop computers :
The most common type of personal computer is the desktop computer-a PC that  designed to sit on (or under) a desk or table. These are the systems you see all around you, in schools, homes, and offices, and they are the main focus of this material

Today's desktop computers are far more powerful than those of just a few years ago, and are used for an amazing array of tasks. Not only do these machines enable people to do theirjobs with greater ease and efficiency, but they can be used to communicate, produce music, edit photographs and videos, play sophisticated games, and much more.

Workstations:
A workstation is a specialized; single-user computer that typically c has more power and features than a standard desktop PC . These machines are popular among scientists, engineers, and

animators who need a system with greater-than-average speed and the power to perform sophisticated tasks. Workstations often have m large, high-resolution monitors and accelerated graphics-handling capabilities, making them suitable for advanced architectural or engineering design, modeling, animation, and video editing. Note that due to rapid technological advancement, the difference between desktop and workstation are very thin or almost invisible.

Notebook Computers:
Notebook computers, as their name implies, approximate the shape of an 8.5-by inch notebook and easily lit inside a briefcase. Because people frequently set these devices on their lap, they are also called laptop computers.
Notebook  computers can operate on alternating current or special batteries. These amazing devices generally weigh less than eight pounds, and some even weigh less than three pounds!

use, the computer's lid is raised to reveal a thin monitor and a keyboard. When not in use, the device folds up for easy storage. Notebooks are fully functional microcomputers; people who use them need the power of a full-size desktop computer wherever they go  Because of their portability, notebook PCs fall into a category of devices called mobile computers-systems small enough to be carried by their user. 

Tablet PCs:

The tablet PC is the newest development in portable, full-featured computers. Tablet PCs offer all the functionality of a notebook PC, but they are lighter and can accept input from a . special pen-called a stylus or a digital pen-that is used to tap or who directly on the screen. Many tablet PCs also have a built-in

microphone and special software that accepts input from the user’s voice.

Handheld PCs:
Handheld personal computers are computing devices small enough to fit in your hand . A popular type of handheld computer is the personal digital assistant (PDA). A PDA is no larger than a small appointment book and is 'normally used for special applications, such as taking notes, displaying telephone numbers and addresses, and keeping track of dates or agendas. Many PDAs let the user access the Internet through a wireless

connection, and several models offer features such as cellular telephones, cameras, music players, and global positioning systems.

Smart Phones:
Some cellular phones double as miniature PCs . Because these phones offer advanced features not typically found in cellular phones, they are sometimes called smart phones. These features can include Web and e-mail access, special software such as personal organisers, or special hardware such as digital cameras or music players. Some models even break in half to reveal a miniature keyboard.

Characteristics of Computer

Speed: Computers can access information and process in fractions of less than a millionth of a second. They are very fast in doing calculations. The processing speed is usually measured in MIPS (millions of instruction per second).

Memory Capacity: Computers have more memory capacity in order to store large volumes of data, information and instructions and to retrieve that information whenever required.

Accuracy: Computer solves any typical problem with high accuracy. If an error occurs it may be only due to human mistakes, which is quite common.

Diligence: Computers can work for hours together which is not possible with humans because of fatigue. So working of computers is not a time-constraint.

Repetitiveness: Computers have the capacity to repeat any operation any number of times. This makes any work to be completed in a short span of time.

Reliability: computer possesses high reliability in all its activities. It can produce fast and accurate results whenever operated, at any instance for any number of times.

Endurance: endurance indicates lifetime of the computer system. Though computers can perform any function repeatedly any number of times they do not show any weakness after serving a certain period of time

Versatility. the computer is so versatile that it can be connected to any internal or external device. This characteristic makes the computer to control any device that is connected to it.