The document provides an overview of operating systems and applications software. It discusses how operating systems control computer resources and enable the running of applications. Common desktop operating systems include Windows, Mac OS, Linux, and Unix. The document also summarizes different types of applications software like word processors, spreadsheets, databases, presentations, and internet browsers. It briefly outlines mobile apps, software licenses, and computer networking concepts.
2. Operating Systems
• Operating System is a program that controls the computer and enables it to run applications software. It allows the computer
to manage its internal resources.
• Allows the computer system to manage its own resources (disks, monitor, keyboard, and printer).
• It runs the basic computer operations - it tells the hardware what to do and how, and when to do it. Applications software
cannot run without system software.
• Common desktop operating system software includes:
• MS Windows – provides an easy interface between the computer and the user. It uses pictures (graphical representations)
which look like push buttons on the screen and you can use the mouse to press them. This interface is known as a Graphical
User Interface (GUI).
•
MS Windows comes in a variety of versions. It has been updated over the years to make it more powerful and easier to use.
• Macintosh Operating System (Mac OS) – is the standard operating for Apple Corporation’s Macintosh computers. Like
Windows, the MAC OS has a GUI interface.
• Linux
• Unix
• OS/2 Warp
• Tablets and smartphones also include operating systems that provide a GUI and can run applications (Android, iOS (for iPads
& iPhones), and Windows Phone). These operating systems are developed specifically for portable devices and therefore are
designed around touchscreen input.
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3. Operating Systems
•Applications software are programs
that help the user carry out specific
tasks on the computer.
•Application software falls into two
categories:
•Tailor-made (or custom-written)
software
•Off-the-Shelf (or packaged) software
4. Operating Systems
• Off-the-shelf software includes:
• Word-processing programs (e.g. MS Word, Writer) – used to prepare text-based
documents such as letters, memos, reports etc.
•
• Spreadsheet programs (e.g. MS Excel, Calc) – used to analyse and
summarise numerical data. Spreadsheets are commonly used in accounting
environments to prepare balance sheets and financial reports.
•
• Database programs (e.g. MS Access, Base) – used to organise and manage
large quantities of data. Databases enable efficient manipulation of data.
•
• Presentation graphics programs (e.g. MS PowerPoint, Impress) – used to
organise text and numeric data in an appropriate format to be displayed to a
group of people. Typically presentations are used in the preparation of on-screen
displays, overhead transparencies and 35mm slides.
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5. Operating Systems
• Photoediting programs (e.g. MS PhotoEditor, Adobe PhotoShop, GIMP) – used to alter images
and graphics. These programs are used to change the size of pictures, crop pictures, adjust the
colours of pictures etc.
• Desktop publishing programs (e.g. MS Publisher, Adobe InDesign) – used to prepare high
quality printed material e.g. flyers, invitations, posters, reports, magazines, and books.
• Internet Web Browsers (e.g. MS Internet Explorer, Google Chrome, Mozilla Firefox, Opera) –
used to locate and display information at Web sites. Browsers display Web pages with text,
graphics, sounds and video-clips.
• Communications software (e.g. MS Outlook, Mozilla Thunderbird) – used for the transmission of
electronic messages or documents between different computers.
• Social Networking websites (e.g. Facebook, LinkedIn) – allow users to be part of a virtual
community. These websites provide users with simple tools to create a custom profile with text and
pictures. A typical profile includes basic information about the user, photo albums, videos and
comments published by the user. People use social networking sites to add friends, send
messages to other users, and leave comments directly on friends' profiles. Some people join
special interest groups on social networking sites.
• Mobile applications (or mobile apps) – are software programs designed to run on smartphones,
tablets and other mobile devices. These programs are usually available through application
distribution platforms (e.g. Apple App Store, Google Play, Windows Phone Store etc.). Some
mobile apps are free, while others must be bought. Mobile apps include email, calendar, contacts,
weather information, location based services, banking, order-tracking and ticket purchases.
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6. Internet Research - Software
•End-User Licence Agreement
•Software Licences:
•Proprietary software
•Open source
•Trial version
•Shareware
•Freeware
9. Data Transfer Rate
• How fast data is transferred from one location to another
•
• Data is transmitted in characters or collections of bits. The
transmission speed of data is measured in:
• bps – stands for bits per second. 8 bits = 1 character
kbps – 1000 bits per second
• mbps – 1,000,000 bits per second
• gbps – 1,000,000,000 bits per second.
11. Dialup Connection
• Uses telephone lines
• Modem dials a telephone number and connects to the
ISP.
• Inexpensive
• Slower than broadband
• No telephone service allowed simultaneously
12. Broadband connection
• Permanent connection to the internet
• Computer is more prone to hacking
• Flat-rate monthly fee
• Fast data transfer between computers connected to the
internet
13. ADSL (Asynchronous Digital
Subscriber Line)
•Uses a modem and a telephone line to
connect to the internet
•The telephone line can be used
simultaneously
•Faster than dial-up connection
•Downloading is faster than outgoing
data
14. Cable broadband
• Uses a modem and the cabling infrastructure
used for cable TV
• The cable modem connects to the computer
via a local area network (LAN)
• Incoming data (downloading) is significantly
faster than outgoing data (uploading).
• The cost of a cable connection is similar to an
ADSL connection.
15. Wi-Fi
•Uses radio transmitters and receivers to
link computers
•Public areas provide wireless local area
network hotspots
•Many smart phones support wireless
connectivity
16. WiMax
• A wireless communications standard similar to
Wi-Fi, but supports a far greater range of
coverage
• WiMAX station can cover a range of up to 50km
Satellite broadband
• An Internet connection that requires the
installation of a special satellite dish.
17. Protected & Open Wireless
Network
• Wireless networks appear only if your laptop has a
wireless network adapter and driver installed and the
adapter is enabled.
• Protected/secure or open
• Wireless networks that do not have
security enabled (i.e. open networks)
will be identified with a yellow shield icon.
18. Password policies
• At least 6 characters long
• It should consist of both upper and lower case
letters and also one or more numbers
• Date of birth, phone number and words found
in dictionaries do not constitute a good
password
• Passwords should be changed regularly
19. Firewall
• A system designed to prevent unauthorised
access to your computer system when
connected to Internet
•Filters information coming through the
Internet connection
• If an incoming packet of information is
flagged by the filters, it is not allowed
through
20. Backing Up Data
•Copying of data files to a secondary
storage medium as a precaution in case
the first medium fails.
•Regularly
• At least two backups
• Off-site storage
•Special-purpose backup utility program