Computer System

Hardware - the physical components of the computer, including the computer itself and matched peripherals.
  Internal hardware
     Located inside the main box of the computer
           Processing - transforming data into information
                              - Microprocessor is simply a small processor fabricated on a chip of silicon
Storage devices - Used to store data on or access data from storage media
     Ex: Hard drives, DVD disks and drives, USB flash drives, etc.
Communications devices - Allow users to communicate with others and to electronically access information
     Ex :Modems, network adapters, etc.

  External hardware
       Located outside the system unit and plug into ports located on the exterior of the system unit.

       Input devices     - getting data into the computer
                                  - enable users to get data into the computer for processing

       Output Devices - displaying the information
                                  - enable users to see and/or produce processed informations

Software - the programs that runs on the computer. Refers to any program that tells the computer system what to do.

Categories of Software:
1. System Software - Background programs that control a system.
                                 - A term referring to any a computer software
                                  which manages and controls the hardware so that application software can perform a
                                   task.
                                  Examples: Operating Systems, Compiler, Loader, Linker, Interpreter.

Operating System (OS) - Monitors and controls all input / output and processing activities within a                                                      computer system.
                                         - It is a program that controls the PC hardware and the operation of all other                                                programs

                                      Some Well Known Operating Systems:

                                      DOS - Disk Operating System - one of the first operating systems for the                                                 personal computer. like c:\ >. This is called a command-line interface.

                                      Windows - The Windows operating system, a product of Microsoft, is a                                                        GUI(graphical user interface) operating system. This type of "user friendly"                                                     operating system is said to have WIMP features:
                                         Windows Icons Menus Pointing device

                                       MacOS - Macintosh, a product of Apple, has its own operating system with a                                               GUI and WIMP features.

                                       Unix - Linux (the PC version of Unix) - Unix and Linux were originally created                                         with a command-line interface, but recently have added GUI enhancements.

 Platform is defined by a processor and an operating system.
Software created to run a specific platform won’t run on other platforms. Modern Wintel platforms, such as Windows ME and Windows 2000, are backward compatible, allowing programs written for earlier Microsoft platforms to be run on modern systems.

        Before choosing a platform, consider the following:
            1. Availability of appropriate commercial applications software for the platforms.
            2. Compatibility of platform with existing hardware, software, and expertise

2. Application Software – Programs that allow a user to perform specific tasks on a computer.
         Example: Payroll systems, Inventory Control, Manage student database, Word Processor,                                           Spreadsheet and Database Management System etc.

      Word Processing
         A text editing program, which allows the user to type, compose and correct manuscripts without the need to re-type, when errors changed.

       Types of Word Processors: WordStar, Word perfect, Microsoft Word

        Electronic Spreadsheet
            A program replacing the traditional financial modeling tools that offer modern improvements in ease           of creating, editing, and using of financial models and graphical representations.

        Kinds of Electronic Spreadsheet: Lotus 1-2-3, MS EXCEL, QUATTRO, FRAMEWORK

3. Open Source Software – is a computer software whose source code is available under a license that permits users to use, change, and improve the software, and to redistribute it in modified or unmodified form.
Well-known OSS products : Linux, Netscape, Apache, etc.,

4. Proprietary Software – (also called non-free software)
a software with restrictions on using, copying and modifying as enforced by the proprietor
Proponents of proprietary software are Microsoft.
Example: CAD, Norton Antivirus etc.,

People ware - People who use a computer to obtain information or Computer users
(end users)
          Ex: Computer professionals include:
             Programmers, Systems analysts, Computer operations personnel