Lecture 4:Software
Tonga Institute of Higher EducationIT 141: Information Systems
Introduction
Computer software determines the tasks a computer can help you get
Software helps you Create documents Block viruses Make your computer’s performance better
Software Categories Computer program: instructions that tell a
comp how to carry out at task These programs software Software prepares a comp to do a specific
task (e.g. photo editing, virus protection, file management, or Web browsing)
Programs are written in a computer language that the computer can understand.
Typical languages might be called C, C++, Java
Software Categories
Application Software
Also known as an application or app Examples:
Productivity software Groupware: designed to help several people
collaborate on a single project using local networks or Internet connections
Utility Software
Help monitor and configure settings for comp system equipment, the OS, or the application software
E.g. setup wizards, security software, diagnostic tools
Desktop widgets: desktop widgets include clock, calendars, sticky notes, etc.
Device Drivers
Software that helps a peripheral device start communication with a computer
For printers, screens, modems, storage devices, scanners, sound cards etc.
Document production software
Word processing software: MO Word Desktop publishing software Spreadsheet software: MO Excel Statistical software Database Software: MO Access
Database Software
Database: collection of data that is stored on one or more computers
Database software helps you enter, find, organize, update and report information in a database.
Record holds data for a single entity Field holds one item of data relevant to
a record
Other application software Graphics Software: Microsoft Paint,
Adobe Photoshop Music Software Video Editing and DVD authoring Educational and Reference Entertainment Business
Buying software Essential applications
OS, browser, word processing, security suite, graphics viewer, drivers, entertainment.
Should ONLY have one security software Check system requirements Copyright: form of legal protection that
grants the author of an original work an exclusive right to copy, distribute, sell, and modify that work,
Software license
Software license: agreement Single-user license limits use to one person at
a time Site license allows software to be used on all
computers at a specific location Multi-user license: allows allocated number of
people to use the software at any time Concurrent-use license allows a specific
number of copies to be used at the same time
Different software licenses
Public domain software Proprietary software Commercial software Demoware Shareware Freeware Open source software
Installing Software and Upgrades
Inside a software package there is an executable file with an .exe file extension, support programs with a .dll file extension, data files and sometimes share some common files with other software. This can be supplied by the OS.
.exe
.txt.bmp.hlp
Processor
.dll.ocx
Installing Software and Upgrades
Software Installation
Software installation: process that places a program into a computer so it can be used (run or executed)
Installation procedures depend on the computer’s operating system and whether the software is a local, Web, or portable application.
Local Application
Local Application: software that is designed to stay on a computer’s hard disk.
Most local applications contain a setup program to show you how to install
Windows Registry
This is database that keeps track of your computer’s peripheral devices, software, preferences, and settings.
When you install software on the hard disk, information about the software is recorded in Registry.
This is a means of protecting software from illegal copying It requires users to enter a product key or activation code Can be activated over the phone or Internet
Product activation
Portable Software
It is made to run from removable storage such as a CD or USB flash drive
Program files do not exist on the hard disk
E.g. – Thunderbird (e-mail)
Web Application (Web app)
Software that is accessed with a Web browser
E.g. – Gmail, Yahoo!, Google Earth
Software Updates
Software publishers regularly update their software to add new features, fix bugs, and update its security
Types of software updates include new versions, patches, service packs.
Software updates
Software patches: small section of program code that replaces part of the software you currently have installed
Service pack is a set of patches that correct problems and address security vulnerabilities.
They are usually free
Uninstalling software
DOS – remove by deleting its files Windows and Mac OS – uninstall routine
which deletes the software’s files from various folders on your computer’s hard disk
Security software basics
Security software – protect comps from various forms of destructive software and unauthorized intrusions
Different types – antivirus, anti-spyware, anti-spam, and firewalls
Malware software
Any computer program designed to surreptitiously enter a computer, gain unauthorized access to data, or disrupt normal processing operations.
Viruses, worms, Trojans, bots, and spyware
Malware software
Created by hackers, crackers, black hats, or cybercriminals
Annoy, disrupt operations, identity theft, or organized crimes
Computer virus
Set of program instructions that attaches itself to a file, reproduces itself, and spreads to other files
Viruses DO NOT spread themselves from one computer to another
Signs – displaying annoying messages to corrupting data on the hard disk
Computer worm
Self-replicating program designed to carry out some unauthorized activity on a victim’s computer
Can spread themselves from one computer to another without any assistance from victims
Mass-mailing worm spreads by sending itself to every address in the address book of an infected comp
Trojan horse (Trojan)
Computer program that seems to perform one function while actually doing something else.
Unlike a worm a Trojan is NOT designed to spread itself to other computers
Not designed to replicate
Trojan horse
Keylogger – steal password Remote Access Trojan – allow remote
hackers. Using a victim’s computer as a relay station for breaking into other computers
Bot / intelligent agent
Software that can automate a task or autonomously execute a task when commanded to do so
Behaves like a robot so it is often called bot Good bots – helpful Bad bots (zombies) – destructive Botnet – network of bot-infested comps
Spyware
Type of program that secretly gathers personal information without the victim’s knowledge, usually for advertising and other commercial purposes
What does malware do?
Carry out a variety of unauthorized activities
How do you know if your comp is infected? Irritating messages or sounds Frequent pop-ups Slower response Missing files etc.
Rootkit and virus hoax
Rootkit - Software tools used to hide malware and backdoors that have been installed on a victim’s computer.
Virus hoax – warnings about a supposedly new virus on the loose
Security Suites
Combines several security modules to protect against the most common types of malware, unauthorized access, and spam.
E.g. – Norton 360
Antivirus modules
Type of utility software that looks for and eradicates viruses, Trojan horses, worms, and bots.
How does it work? Software scans for virus signatures in
programs, data files, incoming/outgoing emails and attachments, and inbound instant message attachments.
Antivirus modules
Antivirus software periodically need to be updated Might need a patch or update to fix bugs or
improve features List of virus signatures has to be updated to
keep up with the latest malware developments Virus definition – files that store virus signature
and other information used to erase malware
Antivirus modules
Use Antivirus to scan your computer frequently
Make sure that the virus signature is up to date
Summary
Software Application software Installing software The Window Registry Copyrights Malware Antivirus