CIT 100 1

SoftwareNorm DowneyCIT 100

Systems vs. Application Software

• Controls the hardware

• Runs the computer system

• Operating systems (OS)

• Disk management tools

System Software

• Provides services for people

• Programs to perform tasks

• Word processor, spreadsheets and database

Application Software

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System Software

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System Software

• Includes all programs needed for a

computer and its peripheral devices

to function smoothly

•Consists of two parts

▫Operating Systems (OS)

▫Utilities

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What does an Operating System do?

• Starts computer – Booting Up

• Manages applications

• Manages computer memory

• Handles inputs and outputs

• Provides user interface

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Booting Up

• Booting Up is the term for the process of loading the

operating system from the hard disk into RAM

• Two types of boots:

▫ Warm – PC already on – restart

▫ Cold – PC not already on

• The OS Kernel is the core part of the OS and must be

loaded in RAM memory for the computer to function

▫ RAM available = Total RAM – OS Kernel

▫ For example:

If your PC has 2 GB of RAM, and the OS Kernel takes up ½ a

GB of RAM you have 1½ GB of RAM left for other software

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Managing Applications and Memory

• Pre-emptive Multitasking

▫ The OS controls applications access to computer memory

to ensure each has “fair” access to computer resources

• Virtual Memory

▫ Method of using a computer’s hard disk as an

extension of RAM

▫ When RAM is full, data is swapped back and forth from

RAM to the hard drive

▫ Hard drives are slower than RAM – to make any PC

faster, get as much RAM as possible

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Managing Memory: Virtual Memory

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Providing the User Interface

•The User Interface is the part of the operating system that the user (you, the human) sees and interacts with

•User Interface allows user to:▫ Start applications

▫ Manage storage devices

▫ Shut down computer safely

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Types of User Interfaces

• Command Line▫ Type in text commands at a prompt on the screen▫ No mouse, no icons▫ Examples of Command Line Interfaces include:

DOS Unix

• Menu

• Graphical User Interface (GUI – Pronounced “gooey”)▫ Use mouse to click icons to access files or start programs▫ More user friendly than command line operating systems▫ Examples of GUI’s include:

Windows (all varieties) Mac OS Ubuntu (a version of Linux)

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Command Line Interface

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Graphical User Interface: Windows 7

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Graphical User Interface: Ubuntu Linux

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What’s Linux?

• Free operating system based on Unix

• Forms the underpinnings of Android

• Comes in several versions:

▫ Unbuntu

▫ Debian

▫ Many, many more

• So what’s Unix?

▫ An operating system created at Bell Labs in the late

‘60’s. Because Bell wasn’t allowed by law to sell

software, they gave it away for free

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Graphical User Interface: Mac OS X

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Not All Graphical User

Interfaces are on

Computers

Smartphones also use

GUIs

Including Android

phones, iPhones, etc.

Screen shot of Smartphone

Android OS

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System Utility Software

• Backup software

• Antivirus & Security Software

• File Managers (usually handled by Windows)

• Scanning & Defragmenting software (Norton

Utilities)

• File Compression (usually handled by

Windows)

• Accessibility Utilities (Kurzweil)

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Other terms to know:

• Device Drivers

▫ Software that allows OS to communicate with and

control peripheral devices such as printers & scanners

• PnP – Plug and Play

▫ OS detects and configures the use of new hardware

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Applications Software

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Application Software

• Programs users (people) use to get work done

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Application Software

Tailor Made

Custom Software

Packaged Software

General Purpose

See Next Slide

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General Purpose Software

Personal

Productivity

Multimedia &

Graphics

Internet

Programs

Home &

Education

Word ProcessingDesktop

publishingWeb Browsers Personal Finance

Spreadsheet Drawing E-mail programs Tax Preparation

Presentation Image editing Instant Messaging Home Design

Database Video editingVideo

Conferencing

Reference (maps,

encyclopedias,

etc.

Personal

Information MgmtAudio Games

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Personal Productivity

• Word Processing (MS Word)

▫ Document production

• Spreadsheet (MS Excel)

▫ Numeric analysis software used for carrying out “what

if” scenarios.

• Presentation (MS PowerPoint)

▫ To create visual aides to accompany a presentation

• Database (MS Access)

▫ For managing and querying data records

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Software Suites

• A collection of application software packages sold

together

• Examples:

▫ Microsoft Office

Word, Excel, PowerPoint, Access, Outlook, Visio, One

Note

▫ Adobe Creative Suite

Photoshop, Illustrator, Flash, Dreamweaver, Fireworks,

Acrobat

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Tailor Made Software

• Custom software▫ Designed to meet specific needs

▫ Expensive

• Packaged Software▫ Designed to be used out of the box

▫ Can be customized

▫ Cheaper than Custom Software, but still expensive

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Software System Requirements

• Minimum level of computer equipment

needed for software to operate

• System Requirement specify:

▫ Platform (Operating System)

▫ Minimum CPU or processor speed

▫ Minimum amount of RAM required

▫ Minimum disk space for installation

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Version Numbering

• Examples:

▫ Windows 7.0 (which is really 6.1)

▫ MS Office 2010 (Marketing name only – really it’s

MS Office version 14)

• X.Y

▫ X – Major program revision

▫ Y – first number after decimal – maintenance

release – bugs fix

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Licensing

• Copyright▫ Defines rights legally granted to the creator of a

piece of software

• Software license▫ Contract distributed with software, giving the user

rights to install and use it

• Site license▫ Contract between software maker and large

organizations granting the right to install software on a large, but specified number of computers at a discounted cost

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Software Registration

• Validation – requirement for special codes to

install software – protects against theft

• Registration

▫ Indicating, usually online, that you own the

software

▫ Entitles user to updates and product news

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One more term to know…

• Backward Compatibility

▫ Ability to run some older program on a

newer system

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Computer Networks

Norm DowneyCIT 100

What is a network?

A group of two or

more computer

systems linked

together to

exchange data and

share resources

such as expensive

peripherals

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Internet

Remember that TCP/IP thing?

Transmission Control

Protocol (TCP)

Divides transmitted data

into small packets for

transmission,

reassembles data packets

upon delivery into a

complete message

Includes error checking

information

Internet Protocol

(IP) Address

Numeric address that

uniquely identifies each

device on a computer

network

Four sets of numbers (0-

255) each separated by a

dot

Example: 128.30.52.38

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All modern computer networks rely on TCP/IP Protocols

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Advantages and Disadvantages of

Networking

Advantages

Lower hardware costs

Application and

information sharing

Centralizing data

management

Connecting people

Disadvantages

Loss of autonomy(can’t install/uninstall software)

Lack of privacy

Security threats

Loss of productivity

Network Types

PANs

LANs

MANs

WANs

Intranet

Virtual Private Network (VPN)

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PANs

Personal Area Network

The wireless interconnection of

personal information technology

devices within the range of a single

person

Mostly associated with Bluetooth

technology

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PANs Transmission Media

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Infrared

Wireless using light

Limited to line of sight of about 100 feet

Bluetooth

Named for 10th century Viking king

Limited to 30 feet and 8 devices

Uses radio signals – not limited to line of sight

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LANs

Local Area Network

A computer network that spans a

relatively small area.

Most LANs are confined to a single

building or group of buildings.

Home Wireless LAN

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A typical wireless home network

uses a single wireless access

point/router to connect the

home LAN to an ISP. Each node

on the home LAN connects using

a NIC or other wireless adapters.

MANs

Metro Area Network

Bigger than LAN, smaller than WAN

Data network designed for a town or city

Usually characterized by very high-speed

connections using fiber optical cable or other

digital media

CCAC’s network connecting all campuses and

centers is an example of a MAN

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WANs

Wide Area Network

Computer network that spans a large

geographical area. Typically, consists of

two or more (LANs)

Often connected through public

networks, such as the telephone system

The largest WAN in existence is the

Internet.

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Intranet, Domains & VPNs

Intranet

A private network that utilizes Internet and Web

protocols and software

Domains

A network composed of clients and servers under the

control of one central database stored on a server

called a domain controller

Virtual Private Network (VPN)

Designed to provides a secure, encrypted connection

to transmit the data between the remote user and a

company network41

LINKING IT ALL UP

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Nodes

Any device (computer, printer, network

storage devices, etc.) on a network

All nodes are also known as a clients

Each node is uniquely identified on the

network using a numeric network address

Most networks use the IP protocol to identify

each node

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Network Interface Card (NIC)

Expansion cards inside system unit

Can be designed to work with one or more types of cabling

Each Node on the network has some type of NIC

NIC is also known as a Network Adapter

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Network Devices

Routers

Device used to connect two or more networks

Determine best path to route data

Can be used to connect a LAN to Internet

Hubs & Switches

Controls flow of data between nodes within a single

network

Wireless Access Point

Allows nodes to connect wirelessly to a wired

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Networking Media

Twisted Pair

• consists of pairs of twisted wires covered with an insulating layer.

Coaxial cable

• consists of an inner conductor wire surrounded by insulation, a conductive shield (usually a layer of foil or metal braiding), and a cover.

Fiber Optic

• consists of extremely thin strands of glass or plastic bound together in a sheathing (a jacket), transmits signals with light beams.

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Ethernet

Most popular LAN standard

Generally comes in the following speeds

10 Mbps

100 Mbps (Fast Ethernet)

Also Gigabit Ethernet (1Gbps or 1000 Mbps)

Ethernet cable plugs in to an RJ-45

connector

Firewalls

A device or software that blocks

unauthorized access to a network

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CELL PHONES

Can you hear

me now? Yeah, but I’m

not listening.

Telecommunications

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The electronic transmission and reception of

signals for communications.

Convergence & Digitization

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Convergence

Merging of disparate objects or

ideas into new combinations

Example – phone, MP3 player and PDA

Newspapers, TV & radio

Digitization

Transformation of data such as

voice, text, graphics, video and

audio into a digital format

Digitization makes convergence

possible

Cell Phone Generations

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1G – 1981 – Analog mobile phones

2G – 1992 – Digital signal provided:

Decreased interference

Improved reception

Reduced chance of eavesdropping

2G phones are sometimes referred to as PCS

(Personal Communications Service)

3G – 2001 – Faster data transfer rates allowing

voice, data and multimedia transmissions

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4G & LTE

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4G is Mobile broadband technology enabling

IP-based voice, data and multimedia

streaming at speeds between 100 Mbps and

1Gbps

LTE (Long Term Evolution) is a stepping

stone technology on the way to true 4G

VoIP – Internet Telephony

Voice over Internet Protocol

Not a cell phone technology

Uses the Internet’s packet switching

technology to send voice data “packets”

Skype & Vonage

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NETWORK STRUCTURES

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Peer to Peer (P2P)

All computers on

network are “equals”

Good for home use

Not good for

businesses that need

file security or for

networks of more

than 12 computers

(nodes)

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Client/Server Networks

Network includes file

servers and client

computers

Servers serve up files

and services to the

requesting client

Used in business

settings

More secure than P2P

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Network Topologies

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Bus Ring Star

Wireless Fidelity (Wi-Fi)

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Year Standard Speed

1999 802.11b 11 Mbps

2003 802.11g 54 Mbps

2009 802.11n 600 Mbps

2014 802.11ac 1.33 Gbps

SSID – Service Set Identifier,

The a wireless network name

Wireless Security Protocols

WEP

Wired Equivalent Privacy

The original encryption protocol developed for wireless

networks

WPA

Wi-Fi Protected Access

Introduced as an interim security enhancement over WEP

WPA2

Wi-Fi Protected Access version 2

Significant enhancement to WPA2 over WPA

uses Advanced Encryption Standards (AES)

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Wireless Hotspots

Public location with wireless Internet

connection

Examples include Starbucks, McDonalds & CCAC

Hotspot precautions

Watch for shoulder surfers

Watch out for look-a-like or evil twin networks

Don’t transmit confidential data via public

wireless hotspots

Disable file and print sharing on laptops before

using wireless hotspots61

Other terms to know…

Network Operating System (NOS)

Multi user operating system enabling client

devices to communicate with server and each

other, share network resources and applications,

and send messages within network

Near Field Communications (NFC)

Enables devices to share data via touch

Distributed Computing

Processing of tasks across a group of computers

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Computer Networks

Norm DowneyCIT 100