Transcript Chapter 3 PowerPoint

CHAPTER 3
COMPUTER SOFTWARE
Application Software – The programs/software/apps that we run to do
things like word processing, web browsing, and games.
System Software – Programs such as the operating system and utility
programs that control the computer and its devices and enable application
software to run.
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Functions of an OS (operating system)
During the boot process, the essential portion, or core, of the
operating system (called the kernel) is loaded into memory.
Running Programs/Applications
The most important function for an operating system is to run our
applications/software/programs.
• Multitasking – the ability to run multiple programs simultaneously.
The CPU switches between all the programs quickly to make it
appear they are all running simultaneously.
• Multiprocessing – When a computer has multiple CPU’s or multicore CPU’s and each works on a different task.
• Parallel processing – When a single program is designed to be run
on multiple computers or CPU’s. E.g. when you submit a Google
search, thousands of computers at Google work on your request.
Device management
• Communication by the OS to all hardware (e.g. display, keyboard,
network, printer) is through a device driver.
Functions of an OS (continued)
Disk and File management
• Provide a file system so our files can be stored and retrieved.
Hard disks, floppy disks, DVD’s, and flash drives all have
different file systems.
• File systems may include encryption and compression.
Networking (Internet)
• Communicate to the world through the network card or modem.
• TCP/IP is the most popular networking protocol.
Security
• OS’s provide secure logins, permissions to files and folders,
encryption, firewalls, virus detection, etc.
User Interface
• Most OS’s have a graphical user interface (GUI). Some
computers have a command-line interface.
• The OS provides applications with common interface elements
such as windows, menu bars, text boxes, check boxes, etc.
Categories of OS’s
OS Interfaces:
Command Line
Most computers today have a graphical
user interface (GUI). In the past most
computers had a command-line interface.
Many UNIX computers used for servers still
have a command-line interface. Windows
also has a command prompt.
OS Interfaces: Graphical User Interface (GUI)
Although Xerox is credited for developing the GUI, Apple Mac’s popularized
GUI’s in the 1980’s. Apple’s latest is Mac OSX which runs on top of UNIX.
History of
Microsoft OS’s
Microsoft’s first OS was DOS.
Windows 1.0 - 1985
Windows 3.0 - 1990
UNIX
The UNIX OS was developed at Bell Labs (AT&T) in 1969. Also created at Bell Labs using
UNIX was the C programming language and TCP/IP (Internet’s protocol).
Today, there are many flavors of UNIX:
• Solaris runs on SUN computers
• Mac OSX runs on Apple computers
• Linux is free and will run on PC’s
Linux Mascot
Other notables:
 UNIX is known to be more reliable and efficient than Windows.
 UNIX is widely used by the telecom industry. E.g., every cell phone tower uses a UNIX
computer to switch your calls and log information.
 Since TCP/IP was developed on UNIX, most Internet servers (web, e-mail) are UNIX.
 The kernel (core of OS) and user interface are separate. Therefore, you can use different
shells (interfaces) to access your computer.
 Unlike Windows, UNIX is multiuser (supports multiple users) and can be used on
mainframe computers.
 There’s a good chance you have a UNIX computer in your home. Where?
OS’s for Portable Devices
Symbian OS is
used on many
phones such as
Ericsson, Nokia,
and Samsung.
Palm OS
Windows
Phone 7
iPhone iOS
Android
by Google
Software Categories
Commercial software: copyrighted software that is developed, usually by a
commercial company, for sale to others
Shareware: copyrighted software that is distributed on the honor system; consumers
should either pay for it or uninstall it after the trial period
Freeware: copyrighted software that may be used free of charge (e.g. Firefox)
Public domain software: software that is not copyrighted and may be used without
restriction
Open Source: software that includes the source code so that it may be modified. This
software is usually free and may or may not be copyrighted.
Firmware: another name for software that is embedded in the hardware device. It is
often stored in a ROM chip. Cars have firmware.
Installed vs. Web-Based Software
Installed software must be installed on a
computer before it is run.
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Web-based software is run directly from the
Internet.
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Graphics Software
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Audio Capture and Editing
Software
• For creating and editing audio files, audio capture and audio
editing software is used.
• To capture sound
from a microphone,
sound recorder
software is used; to
capture sound from
a CD, ripping
software is used.
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Video Editing Software
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