Comprehensive Study Guide on Computer Software and Systems

Conceptual Overview of Software

  • Computer software can be compared to human intelligence. In this analogy, the human body represents hardware, while software represents the feelings and thoughts generated by the brain.
  • Activities performed by the human body, such as running, eating, and speaking, are initiated and controlled by the brain. Without these feelings and controls, the body would remain idle. Similarly, a computer system's hardware is initiated and controlled by software.
  • Software is defined as a collection of programs and associated documents that help to control, manage, and integrate computer system components to accomplish specific tasks.
  • A program is a systematic collection of data and instructions designed to perform specific work.
  • A software package is a set of programs specially written to provide the user with precise functionality or to solve specific problems. For example, a word processor package allows a user to create, save, modify, and print documents.

Classification of Software

  • Software is broadly classified into two primary types:
    • System Software
    • Application Software

System Software and the Operating Environment

  • System software helps to activate the computer system and provides an operating environment for application software.
  • Its primary functions include controlling, integrating, and managing individual hardware components.
  • It provides both an operating and a programming environment where users and programmers can create and use application software for daily tasks.
  • System software is categorized into three types:
    1. Operating System (OS)
    2. Device Drivers
    3. Language Processors

Operating Systems (OS)

  • An Operating System is the software that activates the computer and provides a common platform for the user to operate the computer system.
  • It is the first layer of software loaded into the computer memory during the process of booting (Start Up).
  • The main functions of an OS include managing disk access and file processing.
  • Other software applications are loaded within the environment provided by the OS.
  • Popular examples of Operating Systems include:
    • Windows XP
    • Linux
    • MS-DOS
    • Windows Vista
    • Mac OSX

Device Drivers

  • Device drivers are special system software required to activate and recognize computer hardware devices.
  • The computer system cannot work with hardware until the corresponding driver software is installed.
  • The Operating System will not recognize devices connected to the system (such as modems or printers) until the device driver is installed.

Language Processors and Translators

  • A translator program converts programming instructions written in a human-convenient form (natural language like English) into machine codes.
  • Since computers are digital devices, they can only work with digits, specifically 00 and 11.
  • All commands, data, and instructions must be converted into machine code (combinations of 00’s and 11’s) because computer hardware cannot process natural English language directly.
  • There are three types of language translators based on their nature and application processing:
    • Compilers: These systems compile the entire program and translate it into machine code all at once. They create object code and then executive code. Examples include C Program and Pascal.
    • Interpreters: These translators convert source code (program code) in a linear manner. They translate one statement or line at a time and only proceed to the next line after completing the previous one. They do not look at the entire program at once. An example is Beginners All-Purpose Symbolic Instruction Code (BASIC).
    • Assemblers: This is a translator that converts assembly level language into machin called source program.

Utility Software

  • Utility software ensures that a computer works accurately and diligently.
  • Key functions of utility software include:
    • Restoring backups on a computer.
    • Discarding expired and unnecessary files.
    • Recovering data and managing files.
    • Protecting against and neutralizing computer viruses.
  • Some utility software comes attached to the operating system, such as:
    • Text editors
    • Backup utilities
    • Disk defragmentation tools
    • Anti-virus software
  • Specific examples of software associated with utility, security, or office tasks include:
    • Windows 7
    • Windows 8
    • AVG Internet Security
    • Microsoft Office