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SECTION 1: INTERNET (DESKTOP BOOK - pgs 5 - 17)
The internet is a very large collection of computers which are connected to one another using telephone lines or cables. Even though the computers are in different places across the country, and around the world, they are connected together by a network.
The origins of the internet bean in 1969, when the 'Department of Defence of the United States of America' set up a network of computers called ARPANET (Advanced Research Projects Agency Network) which connected over network, one computer in California with three computers in Utah. This was the first step towards the creation of the Internet.
In 1989, Tim Berners-Lee invented the World Wide Web (www.), the first web browser; and the fundamental protocols and algorithms which enables the Web to perform.
The first ever web browser created was this:
One of the ARPANET computers.
Tim Berners-Lee, inventor of the World Wide Web.
In order to connect to the internet, the following are required:
- A computer
- An Internet Service Provider (e.g. Batelco, Neutel, etc)
- Modem
- A telephone line or cable
- Internet Access software
Modem stands for Modulator Demodulator. This allows your computer to use the telephone line or cable to get connected with another computer. Modem converts the 'digital' signals into 'analog' signals and vice versa. There are two types of Modems, Internal and External:
- Internal Modems - It's a device fixed inside the computer. For example, Dial-up modem and WiFi are internal modems.
- Dial-up Modem - operates over a telephone line. It requires a network access phone number, username and password to make a connection.
- WiFi (Wireless) - A modern, updated and more popular way of connecting to the internet, which doesn't use a telephone line. It enables the computer to exchange the data wirelessly (using radio waves) over a network. For example, data card and USB interface.
- External Modems - Connect to the computer via a cable and is placed on your desk. An external modem are more expensive than internal modems.
A Modem (Modulator Demodulator) and Router
A Web browser is a software application that enables the users to access, retrieve and view the information and other resources on the Internet.
Below are some of the most commonly used Web browser operating systems (OS) today, such as Google Chrome, Safari, Opera, Microsoft Edge (formerly Internet Explorer) and Mozilla Firefox.
The first web browser developed was called the 'Mosaic'. It was developed at the National Center for Supercomputing Applications in the early 1990's.
Web Page is a page found on the internet which contains the information in the form of texts, graphics or sound. A web page can be accessed through a web browser. These pages form the building blocks of a website, such as the school website.
KEY TERMINOLOGY:
- Internet - Collection of computers connected to each other.
- WWW - World Wide World
- ARPANET - Advanced Research Projects Agency Networks
- ISP - Internet Service Provider
- URL - Uniform Resource Locator
- TCP/IP - Transmission Control Protocol/Internet Protocol
SECTION 2: E-MAIL (DESKTOP BOOK - pgs 18 - 29)
Electronic mail, or E-mail, is a method of sending and receiving messages from one account to another. It is based on store-and-forward model. E-mail servers can store, accept and forward messages. The messages may also include images, audio or video clips. In simple words, we can define it as a process of sending messages in an electronic form.
Features of E-mail:
- E-mail address is unique.
- Send and receive messages.
- Sends the same message to multiple recipients.
- Compose and reads messages offline.
- Has an address book to save retrieve e-mail addresses.
- Creates multiple folders to organise e-mails.
An example of a 'Hotmail' email account.
A 'Captcha' is a test used in the process of using the internet to ensure that the response is generated by a person. It consists of letters and digits in a distorted manner. You have to type the same letters and digits in the box, and are commonly used to prevent the misuse of e-mail addresses by another person, or restrict an automated fraudulent scam by another computer.
ReCAPTCHA logo.
Example of a CAPTCHA verification.
KEY TERMINOLOGY:
- Header - The header of the message is divided into fields such as sender, receiver, summary and other related information.
- Body - Message itself.
- From - The email address and optionally the name of the sender.
- To - The e-mail address(es) and optionally the name(s) of the message recipient(s).
- Subject - A brief heading of the contents of the message.
- Date - The local time and date when the message was written.
- Inbox - Where the messages are stored in an e-mail account.
- CC (Carbon Copy) - It helps to send the same message to several people at the same time.
- BCC (Blind Carbon Copy) - It also sends the same message to several others at the same time without letting them know that others have been sent the same message.
Section 3: MS WORD (DESKTOP BOOK - pgs 30 - 55)
The bar across the top of the Word application is known as the 'Ribbon'. This includes all the features used for creating a Word document.
'File', 'Home', 'Insert', etc. across the top of the Ribbon are called 'Tabs'.
'Clipboard', 'Font', 'Paragraph', etc. underneath the Ribbon are called 'Groups'.
The bar across the bottom of the Word application is called the 'Status Bar'. This is used for zooming in and out, indicating the page number and word count; and page viewing modes.
The large blank area of the Word document is called the 'Main Body of Text'.
The feature used for inputting the same text at the top of all document pages is called the 'Header'.
The feature used for inputting the same text at the bottom of all document pages is called the 'Footer'.
SECTION 4: MS POWERPOINT (DESKTOP BOOK - pgs 57 - 99)
MS Paint also has a 'Ribbon' bar at the top of the Paint application, which uses various 'Tabs' and 'Groups' of features.
The 'Status Bar' at the bottom of the application indicates the slide number, various slide view modes and also the zoom feature. Furthermore, as an additional feature, 'Notes' can be included for each slide as a reference during PowerPoint Presentations.
To format an image, select it within the slide page and use the various 'Picture Format' tools on the 'Tab' to change the image features.
To make your image(s) and text move/appear during a slide show presentation, select each one and use the features on the 'Animation' tab to make it move.
To make each slide appear in a unique way, use the 'Transitions' tab to select the type of change you would like your slideshow presentation to produce.
SECTION 5: COMPUTER VIRUSES AND THEIR EFFECTS (DESKTOP BOOK - pgs 106 - 119)
A computer virus is a program that is secretly introduced into a system in order to corrupt or destroy data. It infects the computer negatively by altering the way the computer works, without the user's knowledge or permission. It spreads from one computer to another computer. A virus destroys or corrupts the data files on the computer system.
Virus is a Latin word which means 'poison'. Virus stands for 'Vital Information Resource Under Seige'. It does stand alone but needs a host file or program to replicate itself.
You may also define it as an undesirable and unwanted program file or routine that corrupts files, replicates itself, replicate other files or in some other way degrade or even shutdown a computer system.
This diagram demonstrates the different types of Viruses in existence that can affect a Computer.
The first computer virus that was known publicly is 'Elk Cloner'. It was created by Rich Skrenta (a middle school student) in 1982. This virus attached itself to the Apple DOS 3.3 operating system and spread through a floppy disk.
The first PC virus was a 'boot sector' virus called 'Brain'. It was created in 1986 by two brothers to prevent pirated copies of software they had written.
Since the mid-1990's, 'Macro Viruses' have become common. These viruses spread through Excel spreadsheets and other Microsoft Office documents.
Today, one of the most common means of a virus infection is through the Internet. E-mails are also one of the most prominent means to spread a virus.
Elk Cloner, the first publicly known virus in 1982.
Boot Sector viruses reside in the boot sector of hard disk or floppy disk. The boot sector is the area of a hard disk or floppy disk that stores valuable information. They cause damages to the stored information. Some of the boot sector viruses are Polyboot B and AntiExE.
'Brain', the 'Boot Sector Virus created in 1986.
A 'Trojan Horse' is a program that appears to be beneficial at first glance but actually damages the computer once it is run. They can steal the information from the computer. 'Beast' and 'Zeus' are examples of a Trojan Horse. Some examples of damage by Trojans are:
- Corrupting and encrypting files.
- Copying fake links which lead to false websites.
- Opening and closing CD-ROM tray.
- Restarting the computer.
- Randomly shutting down the computer.
- Slowing down your computer.
- Taking screenshots.
- Logging keystrokes to steal information such as passwords and credit card numbers.
An example of a Trojan Horse virus on a monitor.
E-mail Viruses spread through e-mails and the attached files. Once an infected attachments is opened, the virus infects the computer system. Some of these viruses replicate themselves by automatically e-mailing everyone in your e-mail address book.
Example of an E-mail virus.
Other types of viruses are:
- 'File Viruses' which infect programs or executable files (files with .EXE or .COM extension). When an infected program is run, the virus becomes active and infects the executable files on the computer. For example, Cascade and Sunday are file viruses.
- 'Worms' which is a malware program that duplicates itself. This virus does not need any host file to attach. Worms can spread very fast and in great numbers. For example, Sasser and Blaster.
Example of a worm virus.
The various ways a virus can enter the computer system:
- Portable Devices - Floppy Disk / CD / USB Memory Stick, etc. that is already carrying the virus on it.
- E-mail - Virus may enter into your computer system through e-mail attachments.
- Internet - Virus may enter through various malicious websites. This can be through downloading infected files which put your computer at risk.
- Computer Network (Server) - A computer system connected by a large/main computer called a 'server' and constantly share information. Any infected file may spread the virus.
Symptoms of a computer virus:
- The computer might run slower.
- It might corrupt your system files.
- It might might make some programs faulty or corrupt.
- It might steal important information from your computer and send them to other people through the internet.
- Application programs on the computer do not work correctly or smoothly.
- The computer locks up by itself frequently which means that it stops responding to your command.
- It makes endless copies of infected files on the system.
- Strange sounds or beeping noises come from the computer monitor.
- The hard drive often runs out of free space.
SECTION 6: PRINTABLE REVISION WORKSHEETS
To compliment the learning in your child/ren's Computing lessons, why not download these printable worksheets relating to the Topics taught in class and the Desktop: Computer Science Books.
Computing Grade 6.pdfPage updated
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