Computer Software

System software is a program that manages and supports the computer resources and operations of a computer system while it executes various tasks such as processing data and  information, controlling hardware  components,  and  allowing  users  to  use application  software.  That  is,  systems  software functions  as  a bridge between  computer  system hardware and the application software. 

System software consists of four types of programs:

1. Operating system coordinate computer resources, provide an interface between users and the computer, and run applications.

2. Utilities perform specific tasks related to managing computer resources.

3. Device drivers are specialized programs that allow particular input or output devices to communicate with the rest of the computer system.

4. Language translators convert the programming instructions written by programmers into a language that computers understand and process.

Operating system

Functions of operating system:

1.Managing resources. These programs coordinate all the computer’s resources including memory, processing, storage, and devices such as printers and monitors.

2. Providing users interface. Users interact with application programs and computer hardware through a user interface.

3. Running application. These programs load and run applications such as word processor and spreadsheet.

Mac OS is a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. The original version was the integral and unnamed system software first introduced in 1984 with the original 

Macintosh, and referred to simply as the "System" software. 

Unix was also an great example of operating system. It is designed to run on minicomputers in network environments.

Most essential programs of utilities:

• Troubleshooting  that  recognize  and  correct  problems,  ideally before they become serious.

• Antivirus programs that guard your computer against viruses or other damaging programs that can invade your computer system.

• Uninstall programs that  allow  you  to  safely  and  completely remove  unneeded  programs  and  related  files  from  your  hard disk.

• Backup programs that make copies of files to be used in case the originals are lost or damaged.

• File compression programs  that  reduce  the  size  of  files  so  they require less storage space and can be sent more efficiently over the internet.

Examples

Device drivers

   Whenever a new device is added to a computer system, a 

new device driver must be installed before the 

device can be used.

Application software

•     - is all the computer software that causes a computer to perform useful tasks (compare with computer viruses) beyond the running of the computer itself. A specific instance of such software is called a software application, program, application or app.

• The term is used to contrast such software with system software, which manages and integrates a computer's capabilities but does not directly perform tasks that benefit the user. The system software serves the application, which in turn serves the user.

 Example

WORD PROCESSING

• using a computer to create, edit, and print documents. Of all computer applications, word processing is the most common.

To perform word processing, you need a computer, a special program called a word processor, and a printer. A word

processor enables you to create a document, store it electronically on a disk, display it on a screen, modify it by

entering commands and characters from the keyboard, and print it on a printer.

Features are:1. Spelling checker2. Font and Font Size3. Center Aligning4. Word Wrap5. Character Effects6. Grammar Checker

 Spreadsheet

•  is an interactive computer application program for organization and 

analysis of data in tabular form. Spreadsheets developed as computerized simulations of 

paper accounting worksheets. The program operates on data represented as cells of an 

array, organized in rows and columns.

Example

• Integrated packages is  a  single  program that  provides  the  functionality  of    a  word processor,  spreadsheet,  database  manager and more. They are popular with many home users  are  sometimes  classified as personal  or home  software.  Less  expensive  than purchasing  several  individual  application programs and simple to use. 

Computer Processing memory

Computer data storage, often called storage or memory, is a technology 

consisting of computer components and recording media used to retain digital data. It is a core function and 

fundamental component of computers. The central processing unit (CPU) of a computer is what manipulates data by 

performing computations.

Primary storage

Primary storage (or main memory or internal memory), often referred to simply as memory, is the only one directly accessible to the CPU. The CPU continuously reads instructions stored there and executes them as required. Any data actively operated on is also stored there in uniform manner. A 

random-access device allows stored data to be accessed directly in any random order.

Secondary storage (also known as external memory or auxiliary storage), differs from primary storage in that it is not directly accessible by the CPU. The computer usually

uses its input/output channels to access secondary storage and transfers the desired data using

intermediate area in primary storage. Secondary storage does not lose the data when the device is powered down—it is non-volatile. Per unit, it is typically also two orders

of magnitude less expensive than primary storage. Modern computer systems typically have two orders of

magnitude more secondary storage than primary storage and data are kept for a longer time there.

Hard disk drive         is a data storage device used for storing and 

retrieving  digital information  using  rapidly rotating  disks  (platters)  coated  with  magnetic material.  An  HDD retains  its  data even  when powered  off.  Data  is  read  in  a random-access manner,  meaning  individual blocks of data  can  be  stored  or  retrieved  in  any  order rather than sequentially.

Basic types of hard disk:

          An internal hard drive is a hard drive that resides inside the computer. Most computers come with a single internal hard drive, which includes the operating system and pre-installed applications.

         An external hard drive is a typically connect to a USB or FireWire port on the  system unit, are easily removed and effectively provide an unlimited amount of storage.

• Flash memory is  an  electronic non-volatile computer  storage device that can be electrically erased and reprogrammed.

• A floppy disk, or diskette,  is a disk  storage medium composed of a disk  of  thin  and  flexible  magnetic  storage medium,  sealed  in  a rectangular  plastic  carrier  lined  with  fabric  that  removes  dust particles. 

• Magnetic tape data storage uses digital  recording on magnetic tape to  store digital  information.  Modern  magnetic  tape  is  most commonly  packaged  in cartridges and cassettes.  The  device  that performs actual writing or reading of data is a tape drive. Autoloaders and tape libraries are frequently used to automate cartridge handling.

• A punched card, punch card, IBM card, or Hollerith card is  a piece  of stiff  paper  that  contains digital information  represented  by the presence or absence of holes in predefined positions.

• Special service sites on the Web provide users with storage. This storage is called an Internet hard drive. Advantages of Internet hard drives compared to other types of secondary storage include low cost and the flexibility to access information from any location using the Internet.

Examples

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