Revision Notes for Class 10 IT (402) – Chapter 3 ICT Skills II

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ICT skills help us to communicate, run our business and stay connected with our family and friends. Hence, every person needs to acquire ICT skills and build them to stay updated with the latest software and applications (apps).

Computer Hardware and Software

A computer system consists of two main parts—

  1. Hardware: The physical parts that we can see and touch are called hardware. It is the machinery of a computer. These are the keyboard, monitor, CPU, etc.
  2. Software: The part which cannot be seen but it makes hardware to work. Example: Windows, MS office etc.

Operating System

An operating interface between user and computer which directs the processing of programmes and controls the operation of computer.

Some of the functions of Operating system are:

  • It supervises all the hardware on a computer and monitors each device’s status, including whether it’s in use or not.
  • It also checks whether the device is functioning properly or not.
  • It also controls software resources of the computer.
  • It controls how much memory is used by the computer, keeping track of which memory is free and which memory is being used by which software.
  • It controls how a computer system’s files and directories are organized.
  • It keeps track of the amount of disk space used by a specific file.
  • It allows you to create, copy, move and delete files.

Types of Operating Systems

The different types of operating systems are as follows:

  1. Single-user, single-task operating system: This kind of operating system only permits one person to use the computer at a time for one job.
  2. Single-user, multi-task operating system: This kind of operating system is used on desktop and laptop computers, which allow one user to run multiple programmes simultaneously. Examples of single-user multitask operating systems are Windows and Apple MacOS.
  3. Multi-user: A multi-user operating system enables multiple users to work on the same computer at different times or simultaneously.
  4. Real Time: A computing environment that responds to input within a specific period of time, is known as a real-time operating system. It controls the computer’s resources so that each operation is completed in exactly the same amount of time each time. Real-time operating systems include Lynax OS and Windows CE.
  5. Distributed: A distributed operating system runs on a set of computers that are interconnected by a network. It combines the different computers in the network into a single integrated computer and storage location. Windows, UNIX, and LINUX are examples of distributed operating systems.
  6. Interactive (GUI-based): An operating system that is user-friendly has a graphical user interface where commands can be entered by clicking, double-clicking, or right-clicking the mouse. Windows is the example of Interactive Operating System.

Menu, Icons and Taskbar on the Desktop

The components of Windows are as follows –

  • Taskbar: The long horizontal bar at the bottom of the screen is called the taskbar. The Start button is located to the left of the Taskbar, and Date/Time is located to the right. On the Taskbar, you can also see icons for open programmes and a few shortcuts.
  • Start button: It is located on the left of the taskbar. Clicking the Start button opens the Start menu and provides access to programs and features.
  • Recycle Bin: The user’s deleted files and folders are kept in the Recycle Bin. You can restore accidentally deleted files or folders from the recycle bin.

Creating and Managing Files and Folders


Every single thing you keep on your computer is kept as a file. A file system is a method for naming, storing, and retrieving files.

Creating File
  1. Right-click anywhere in the blank area of the right-column.
  2. In the Shortcut menu, click New and select the type of the file you want to create.
Renaming folders and files
  1. Right-click the file or the folder.
  2. From the shortcut menu, select Rename option.
  3. Type the new name or edit the existing name and press the Enter key.
  4. Or Just select the file/folder and press Function key F2.
  5. Right-click anywhere in the blank area of the right-column.
  6. In the Shortcut menu, click New and select the type of the file you want to create.


Folders and directories are groups which contain single of multiple files. There may be related files and/or subfolders in each directory and folder. One or more files and other sub-folders may be located inside a sub-folder. This makes files easily accessible.

Creating Folder
  1. Double-click the Computer icon.
  2. Select the drive in which you want to create a new folder. Say, Local Disk D:.
  3. Window will open up showing files and folders in Local Disc D:
  4. Click New Folder on the toolbar
  5. A new folder is created with name New Folder highlighted.
  6. Type a name for the folderCreating a file
Renaming folders and files
  1. Right-click the file or the folder.
  2. From the shortcut menu, select Rename option.
  3. Type the new name or edit the existing name and press the Enter key.
  4. Or Just select the file/folder and press Function key F2.

Deleting files or folders

  1. Click the file or the folder.
  2. Press the Delete key.
  3. Or Right-click and select Delete option from the Shortcut menu.

Basic Shortcuts

CTRL + z — undo
CTRL + y — redo
CTRL + a — select all
CTRL + x — cut
CTRL + c — copy
CTRL + v — paste
CTRL + p — print
CTRL + s — save.

Apply Basic Skills for Care and Maintenance of Computer

Computer systems require maintenance in order to function properly. System failure may result from poor maintenance. You may be able to keep it in good working order by giving it routine care and maintenance. Installing updates, security, creating backups, and scanning are all part of routine system maintenance.

To keep the computer system’s maintained you should follow the following activity –

  1. Keep the computer dust free.
  2. Do not eat or drink while working on the computer. Food or drink may spill on the system.
  3. To keep the keyboard clean, make sure your hands are clean before using it.
  4. CDs and DVDs should be handled carefully so that it does not get any scratches.
  5. Keep keyboard covered when not in use.

Cleaning the Computer Components

Computer components needs proper care to last longer. Preventive maintenance increases the life of the components.

General precautions to be taken while cleaning the computer components are:

  • Always Power Off the computer system before cleaning.
  • Never spray cleaning fluid directly on the component of the computer. First spray the liquid on the cloth and then wipe the component.
  • Do not allow the cleaning liquid to drip near the circuit board.
  • Preferably use anti-static wrist band which helps to prevent building up of static electricity near electronic device.
Computer monitor

To clean the computer monitor, you can use a soft lint-free cloth, like cotton and water or special cleaning liquid. You should not spray water or cleaning liquid directly on the computer monitor as it may run through the seams.


The keyboard might be harmed by dirt and dust. If dirt gets inside the keyboard’s keys, the keys could not work properly. Every now and then, move the keyboard while holding it upside-down to clean it.

Optical Mouse

With a clean, lint-free cloth, you can clean the optical mouse’s bottom. Air or a cotton swab can be used to clean the lens region.

Digital camera

Never touch the camera’s lens. You can use a soft lens brush or a soft, dry cloth to remove the dust. You can use a special lens cleaning solution to remove tenacious dust, but first you should apply it to a tissue before wiping the lens. Never spray fluid over the lens directly.

CDs and DVDs

Keep CD/DVD in proper case to prevent damage. If there is some dirt on the CD or DVD, it may not work at all. Finger prints and dirt can be removed by lightly rubbing with a clean lint-free cotton cloth.

Preparing Maintenance Schedule

Regular maintenance of the computer system is very important.

Some of the maintenance activities are:

  • Keep the components of the computer, like keyboard, mouse, monitor, etc. clean.
  • Replace hardware that is not functioning properly
  • Keep food items away from the computer
  • Cables and chords should not be messed up
  • Removing unauthorized software from the computer
  • Take regular backup of the data
  • Ensure backups are working properly by periodically restoring or checking of data.

You should use external hard drive for backup of data on your computer.

  • Run anti-virus periodically
  • Keep anti-virus software up to date
  • Do not overcharge the batteries
  • Do not block the vents
  • Always shut down the computer properly

Protecting Computer against Viruses

An Illegal programme known as a computer virus attaches to other programmes and modifies their behaviour. A virus might or might not cause harm. Some viruses damage computer programmes or delete data. Vital Information Resource Under Seize is referred to as VIRUS.

A computer can get infected with virus in any of the following ways:
  • Infected files
  • Infected pen drives
  • Infected CD-ROMs/DVD-ROMs
  • Through infected file attachment of e-mails
A computer virus cannot do the following:
  • It cannot infect files on CD or DVD, if they are closed for writing.
  • It cannot infect computer hardware like, keyboard, mouse, etc.
How do we know that our computer is infected with virus?
  • Computer runs very slow
  • There is change in the file size
  • Computer often stops responding
  • There is an increase in number of files (unusual)
  • Unusual error message appears on the screen
  • Computer restarts on its own

Scanning and cleaning viruses and removing SPAM files, temporary files and folders

  • Install and use anti-virus software.
  • Keep anti-virus software updated.
  • Scan all the files that you download from the Internet
  • Do not open e-mails of an unknown person/sender
  • Don’t allow any untrustworthy person to use your system.
  • New use unknown pen drive/CD on your computer
  • Never click on the windows that pop-up when you are surfing the Internet.

Preparing computer against virus

For an anti-virus program to be work effective do the following:

  • It needs to run in the background at all times.
  • Keep the anti-virus software updated so that it can recognize new viruses.
  • Run full disk scans periodically.

Removing Temporary Files

When you use computer programmes, temporary files are created automatically. A TMP file is also known as Temporary file and it is created in the Microsoft Windows and Windows apps. Web browsers also create temporary files to store your browsing history.

  1. Double-click Computer icon on the desktop.
  2. The Computer Window opens.
  3. Right-click Local Disk C: and select Properties option from the Shortcut menu
  4. The Properties window opens. Click Disk Cleanup.
  5. The Disk Cleanup for C: window appears
  6. Click the Check box next to Temporary Files, Temporary Internet files, etc. that you want to delete.
  7. Click OK.
  8. A confirmation message will appear
  9. Click Delete Files.
  10. Windows will delete all the temporary files on the computer.

Removing Files of Temporary Folder

  1. Press Windows button + R on the keyboard.
  2. The Run dialog box appears.
  3. Type %temp%
  4. The Temp folder opens Click Ctrl + A to select all the files in the folder. Press Delete key.
  5. A message box appears. Click Yes to confirm.


  • A computer firewall is a network security system, software, or programmable device that monitors and regulates incoming and outgoing network traffic in accordance with user-defined security rules.
  • Computers connected to a network, such as a LAN or the Internet, are more securely protected by firewalls.
  • Typically, a firewall creates a wall between a trusted internal network and an unreliable external network, like the Internet. Each packet of data, whether it is coming in or going out, is examined by the firewall, which then decides whether it should be permitted to pass or stopped.


  • When you visit an internet website, a user’s computer stores a little file known as a cookie on it.
  • These files are used to store information personal to a given client and website.
  • A cookie is sent by a website when you visit it and is saved on your computer in a file. A cookie can only be read by the website that created it. This information cannot be accessed by other servers.

Basic TIPS for Taking Care of Devices

  1. Keyboard: You can clean a keyboard with a soft brush
  2. Screen: You can wipe the screen with a soft cloth to remove any finger marks.
  3. Handle devices carefully: Handle and move your laptop carefully and avoid dropping or banging it against a hard surface.
  4. Keep the computer cool: If a computer, laptop or mobile device gets overheated, the internal parts can be damaged. The CPU has an internal fan to keep it cool. We should make sure the fan is functioning.
  5. Do not overcharge your battery: Sometimes we keep a device plugged in for charging even after it is fully charged.This reduces the battery life. Always unplug the device once it is charged 100%.
  6. Always plug in devices carefully: Any device being connected to a laptop or computer such as a USB drive or headphones, should be done gently. It should not be forced into the port.
  7. Do not run too many programs at a time: When too many programs are running at the same time, the computer can become slow and even crash.

Prepare a Maintenance Schedule

  • Daily Maintenance
    1. Clean up your e-mail inbox
    2. Download e-mail attachments and save in proper folders
  • Weekly Maintenance
    1. Clean your keyboard
    2. Clean your monitor
    3. Dust CPU and printer
    4. Backup your data to an external drive
  • Monthly Maintenance
    1. Transfer photographs to computer and delete from drive
    2. Organise photos into folders or albums
    3. Clean up ‘Download’ folder
    4. Uninstall unused programs and apps
    5. Run disk-cleaner software
    6. Run full system virus scan
  • Yearly/Annual Maintenance
    1. Clean up contacts list on social media accounts
    2. Clean up e-mail contact list
    3. Update your operating system
    4. Check for expiry of anti-virus software and renew

Backup your Data

  • Backing up data means to save the information present on your computer on another device, such as CD/DVD drives Data can recovered from here in case the computer stops working completely.
  • Computers can crash, humans can make mistakes and natural disasters, such as floods can happen Scanning and Cleaning Viruses
  • Sometimes computer viruses can enter a computer from such attacks we can install anti-virus software. This will prevent any viruses from entering and will also clean any viruses that may enter our system before they affect the data.

Increasing Computer Performance

If we have been using a computer for a long time we have a lot of unnecessary files and data, such as temporary files and images. When they use too much hard-disk space, the performance of the computer goes down. It is important that we keep cleaning by removing any extra files.

Removing SPAM from your Computer

Sometimes we get emails from companies who are advertising a product or trying to attract you to their website. Such mails are called SPAM. We should never respond to SPAM and delete it on a regular basis.

Threats to Computer

Threats are the ways in which personal information can be leaked from a computer without our knowledge.

  • Theft: Theft means stealing of information or hardware. These may be of three types:
    1. Physical: Where a person may steal your desktop computer or laptop.
    2. Identity: Where a hacker steals your personal information and assumes your identity. Using this false identity, the hacker can gain access to your account information or perform illegal activity.
    3. Software Piracy: This is stealing of software and includes using or distributing unlicensed and unauthorised copies of a computer program or software.
  • Virus: Viruses are computer programs that can damage the data and software programs or steal the information stored on a computer. Major types of viruses are Worms and Trojan Horse.
    1. Worms: These are viruses that replicate themselves and spread to all files once they Information and Communication Technology Skills 81 attack a computer. This makes it very difficult to remove them.
    2. Trojan Horse: A Trojan Horse disguises itself i.e., it appears to be a useful software program but once it reaches a computer it starts behaving like a virus and destroying data.
  • Online Predator: Online predators are people who trap you into inappropriate relationships. They may be older people posing to be your age, bullying you into doing illegal activities online and sometimes face to face.
  • Internet Scams: Sometimes you may receive very attractive offers saying you have won huge money in a lottery and that you can claim the prize by depositing a certain amount of money. When you deposit the money using credit card or online banking, you not only lose the deposit money but your card/account information may be misused later.

Protecting your Data

  1. Use passwords to login to your computer: Use passwords that are difficult to guess. Passwords are difficult to hack if they are a mix of small (For example ‘a b c d’) and capital letters (For example, ‘H J E R’), numbers (For example ‘8 7 6 5’) and special characters (For example, ’% ^ # $’). This would prevent unauthorised people from using your computer.
  2. Install Anti-virus and Firewall: Anti-viruses and Firewall monitor the data coming in and out of a computer and prevent and viruses from entering. Anti-viruses can also detect and clean viruses that may have entered a computer.
  3. Encrypt Data: This is usually done by banks and companies in which important customer information is stored. They can encrypt their entire hard disk using the encrypting feature in Windows (Bitlocker). This would force users to use a decryption password (or key) before starting the computer thus preventing unauthorised usage.
  4. Secure sites: Give details of your credit card or bank account only on secure sites. See in the address bar of the browser. If the site address starts with https://and a lock symbol, then it is safe to give your credit card and bank details.

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