The document discusses computer software and its different types. It defines software and hardware, and explains how software programs work using algorithms. It describes the software development process and types of software, including applications software and systems software. It also discusses operating systems, user interfaces, and how computers boot up when turned on.

1. Computing Fundamentals Module
Lesson 4 — Computer Software
Computer Literacy BASICS

2. Objectives
 Distinguish between software and hardware.
 Explain how a computer software program
works.
 Understand the steps involved in software
development.
 Describe the difference between applications
software and systems software.
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3. Objectives (cont.)
 Describe the three categories of systems
programs.
 Describe operating systems for
microcomputers, including network operating
systems.
 Define a user interface.
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4. Objectives (cont.)
 Explain the difference between a command-
line user interface and a graphical user
interface.
 Understand the boot process a computer
goes through when you start it.
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5. Vocabulary
 Algorithm  Network operating
 Applications software system
 Boot  Operating systems
 Graphical user  Software development
interfaces (GUIs)  Systems software
 Language translators  Unix
 MS-DOS  User interface
 Multitasking  Utility software
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6. Hardware vs. Software
 Computer systems consist of both hardware
and software.
 Hardware has little value without software,
and software cannot run without hardware to
run it.
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7. What Is Hardware?
Hardware refers to anything you can physically
touch:
 The keyboard and the mouse
 The monitor and the printer
 The motherboard and expansion cards
 All the other components in the computer case
or attached to the computer
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8. What Is Software?
Software consists of the instructions issued to
the computer to perform specific tasks:
 The software on a computer system refers to the
programs that make the computer run.
 Software programs are lists of instructions in
code that the computer understands that tell the
computer what to do.
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9. How Software Programs Work
 A computer processes data by applying rules
called algorithms.
 An algorithm creates a logical progression of
steps needed to accomplish a task.
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10. An Algorithm to Solve a
Household Problem: Dirty Laundry
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11. Software Development
Software development is a multistep process
that begins with a need to perform a task
more efficiently using a computer:
 First, the programmer breaks down the problem
into a series of steps in an algorithm.
 The programmer may use a flowchart to show
different paths the program will take.
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12. Software Development (cont.)
 Next, the programmer writes the steps in a
computer programming language or code,
using formal terms and syntax.
 Then the computer translates the code into
machine language it can understand and
uses the translated commands to execute a
program.
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13. Debugging Software
 The software development process does not
end when the computer executes the
program.
 Errors in syntax or even spelling can cause
problems and distort program results.
 Tests of the software find and fix bugs or
errors in the code so it will run properly.
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14. Types of Software
There are literally thousands of software
programs you can buy, but all of them can be
grouped into one of two categories:
 Applications software
 Systems software
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15. Applications Software
 Application software consists of programs
that were created to perform a specific task.
 Application software is also called
productivity software.
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16. Applications Software (cont.)
 The most common types of application
software are
– Word-processing programs
– Spreadsheet software
– Presentation software
– Database software
– Web browsers
– Games
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17. Systems Software
 Systems software refers to the programs that are
used to manage computer system resources.
 Systems software coordinates and controls the
resources and operations of the computer itself.
 The three categories of systems software are
– Operating systems
– Utility programs
– Language translators
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18. Operating Systems
 Operating systems provide an interface
between the user and the computer.
 There are many brands and versions of
operating systems.
 An operating system is designed to work with
a specific processor.
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19. An Operating System Is an Interface
Between Users and Computers
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20. Utility Programs
Utility programs are designed to help perform
housekeeping chores for the computer:
 Manage the computer s resources
 Perform file and folder management tasks
 Clean up unused files from the hard disk
 Defragment disk storage
 Copy files from one disk to another
 Back up data to disk or tape
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21. Language Translators
 Computers cannot read program statements in
programming language format, such as Visual
Basic or Java program statements.
 Language translator programs convert
program language code into machine code that
can be understood by the computer.
 Once converted to machine code, the program
can be run and executed by the computer.
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22. Microcomputer Operating Systems
 If your computer is a Macintosh, you are
probably using a Mac OS.
 If your computer is a PC or is PC compatible,
you are most likely using one of these
operating systems:
– DOS
– A combination of DOS and Windows
– A standalone version of Windows
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23. Mac OS
 Macintosh computers were introduced by
Apple Computer in 1984.
 Macintosh had one of the first GUI operating
systems, with icons that represented
programs, documents, and disks.
 This was also the first operating system to
provide an on-screen help system.
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24. DOS
 IBM introduced its first PC in 1981. Its operating
system was called DOS, which stands for Disk
Operating System.
 DOS is a command-line interface operating
system. The user had to enter commands at a
screen prompt.
 It was a single-tasking operating system, which
meant that only one program at a time could be
executed.
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25. Windows
 Windows was Microsoft s first GUI operating
system, released in 1987.
 The first versions were called operating
environments because they acted as a shell
around the DOS operating system and
worked in combination with DOS.
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26. Windows
 Applications installed on a Windows system
appeared as icons that were activated by
clicking them, similar to the Mac OS Finder
interface.
 The earliest versions of Windows were labeled
Windows 3.0, 3.1, and so on.
 The first true multitasking version of Windows
was Windows 95, which also included support
for networking computers.
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27. Windows
 Windows 98 improved on Windows 95 and
offered Internet integration and support for the
USB bus.
 Windows 2000 was an update to Windows 98
and Windows NT and included tools for Web site
creation.
 The latest version is Windows XP, which
provides increased stability and device
recognition.
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28. The Windows XP Operating System
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29. Other Operating Systems
 Unix was developed by AT&T and is another
early operating system that is still used
today.
 It is a portable operating system, which
means it can run on any hardware platform.
 Variants of Unix include the freeware
operating system Linux and IBM s AIX.
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30. Network Operating Systems
 A network operating system (NOS) is designed
to allow multiple computers to be connected
and talk to each other.
 The most popular networking operating
systems include
– Microsoft Windows NT
– Novell s Netware
– IBM s Warp Server
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31. User Interfaces
 You are probably familiar with the user
interface of an operating system because it is
what you see when you use the computer.
 The user interface determines how user
friendly the operating system is.
 There are two commonly used types of
operating system interfaces, command-line
interfaces and graphical user interfaces.
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32. Command-Line Interfaces
 With this interface, you must type exact
commands into the computer from a
command prompt.
 You must memorize many commands and
keywords.
 Command-line interfaces are not as user
friendly as graphical user interfaces.
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33. Graphical User Interfaces
 Menu-based interfaces were easier to use,
providing options so that commands did not
need to be memorized.
 The breakthrough in ease of use came with
the introduction of graphical user interfaces
(GUIs).
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34. Graphical User Interfaces (cont.)
 Users manipulate on-screen icons to perform
functions, usually with a mouse or other
pointing device.
 Most of today s personal computers are
equipped with some type of user-friendly
GUI.
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35. Comparing User Interfaces
Graphical
Command-Line Interface
User Interface
Icons
Command representing
prompt
programs or files
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36. Starting Your Computer
 When you start your computer, operating system
commands are loaded into memory.
 Each operating system starts the computer in its
own individual way.
 When you turn on a computer, you boot the
system.
 POST (Power-on Self Test), a series of tests that
check RAM and verify that the keyboard and disk
drives are connected to the computer, runs when
you start your computer.
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37. Starting Your Computer (cont.)
 Then the BIOS (Basic Input Output System)
searches for the boot record. The hard disk
drive C is typically the startup drive, so that is
where the BIOS will look first for the boot
record. BIOS is built-in software on a ROM
chip. It contains all of the code that controls
the monitor, keyboard, disk drives, and other
components.
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38. Starting Your Computer (cont.)
 The boot record, which includes several files, is
loaded into RAM. These files contain programming
configuration instructions for hardware devices and
software applications that you may have installed
on your computer.
 Next, the software drivers are loaded. Drivers
enable you to use your printer, modem, scanner,
or other devices. Generally, when you add a new
device to your system, drivers are installed for that
device.
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39. Starting Your Computer (cont.)
 Next to be loaded is the GUI or graphical user
interface, such as Windows XP. When loading
the GUI, the operating system reads the
commands for your desktop configuration. It also
loads whatever programs you have previously
specified into the Windows Startup Folder.
 If everything goes as it should, the GUI displays
the desktop and the computer is ready to use.
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40. Summary
 Hardware refers to anything you can touch.
 Software is instructions that tell the computer
what to do.
 Software is also called a program.
 A computer processes data by applying rules
called algorithms.
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41. Summary (cont.)
 An algorithm creates a logical progression of
steps needed to accomplish a task.
 Software development is a multistep process
that includes writing the command code in a
programming language, having the computer
translate the code into machine language,
and then debugging and testing the program.
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42. Summary (cont.)
 The two basic types of computer software are
applications software, also called productivity
software, and systems software.
 Systems software coordinates and controls the
resources and operations of a computer system.
 Three major categories of systems software are
operating systems, utilities, and language
translators.
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43. Summary (cont.)
 Operating systems provide an interface
between the user and application program
and the computer hardware.
 Utility programs help users complete
specialized tasks, such as file management.
 Language translators convert code written in
English-based software programs into
machine language.
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44. Summary (cont.)
 All computers have operating systems.
 Mac OS is used with Apple s Power
Macintosh computers and Power Macintosh
clones.
 DOS was introduced with the IBM PC in
1981 and is a character-based operating
system.
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45. Summary (cont.)
 Microsoft introduced the first version of
Windows in 1987; this was an operating
environment.
 Windows 95 was Microsoft s first true
multitasking operating system.
 Unix is a portable operating system.
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46. Summary (cont.)
 Network operating systems allow a group of
two or more microcomputers to be
connected.
 The user interface is the part of the operating
system with which we are most familiar.
 The two most common user interfaces are
command-line interfaces and graphical user
interfaces.
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47. Summary (cont.)
 Most of today s computers come with some
type of graphical user interface.
 Icons are symbols that represent documents,
software programs, disks, and so forth.
 A graphical interface includes standard text
and graphics so that data processed in one
application program can be shared by other
applications.
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