Chapter-2 : Introduction to Operating System
2.0 Introduction
Welcome to Chapter 2 of the NIELIT CCC course! In this chapter, we will delve into the fascinating world of Operating Systems (OS). An OS is the most crucial software that runs on a computer, managing all the computer’s hardware and software resources. Without an OS, your computer would be just a collection of inert parts. Think of it as the brain of your computer, coordinating everything to make it user-friendly and functional.
2.1 Objectives
After completing this chapter, you will be able to:
Understand the basic concepts of an Operating System.
Identify different types of Operating Systems used in desktops, laptops, mobile phones, and tablets.
Navigate and customize the user interface of desktop/laptop Operating Systems.
Manage files and folders efficiently.
- Recognize common file extensions.
2.2 Operating System
2.2.1 Basics of Operating System
An Operating System (OS) is a system software that manages computer hardware, software resources, and provides common services for computer programs. It acts as an intermediary between the user and the computer hardware.
Functions of an Operating System :
Process Management: Manages the running programs (processes) to ensure they share the CPU effectively.
Memory Management: Allocates and deallocates memory for various programs.
File Management: Organizes and manages files and folders on storage devices.
Device Management: Controls input/output devices like keyboards, mice, printers, etc.
Security: Protects the system from unauthorized access.
User Interface: Provides a way for users to interact with the computer.
2.2.2 Operating Systems for Desktop and Laptop
Desktops and laptops typically use powerful operating systems designed for multitasking and a wide range of applications. Some of the most popular ones include:
Microsoft Windows: The most widely used OS globally. Known for its user-friendly graphical interface (GUI) and extensive software compatibility. Versions include Windows XP, Vista, 7, 8, 10, and 11.
macOS (formerly OS X): Developed by Apple Inc. Exclusively runs on Apple’s Macintosh computers. Known for its elegant interface, strong focus on design, and robust performance.
Linux: An open-source and free operating system. It comes in various distributions (e.g., Ubuntu, Fedora, Mint). Highly customizable and popular among developers and those seeking alternatives to Windows and macOS
2.2.3 Operating Systems for Mobile Phone and Tablets
Mobile devices require operating systems optimized for touch interfaces, power efficiency, and connectivity.
Android: Developed by Google. The most dominant mobile OS globally, used by a vast array of smartphone and tablet manufacturers. It is open-source and highly customizable.
iOS/iPadOS: Developed by Apple Inc. Exclusive to iPhones and iPads. Known for its smooth, intuitive interface, strong security, and a rich ecosystem of apps.
Other/Legacy OS:
Windows Phone (Discontinued): Microsoft’s mobile OS.
BlackBerry OS (Legacy): Used in older BlackBerry devices.
KaiOS: A lightweight OS for feature phones.
2.3 User Interface for Desktop and Laptop
The User Interface (UI) is what you see and interact with on your screen. Most modern desktop/laptop OS use a Graphical User Interface (GUI).
2.3.1 Task Bar
The Taskbar is a bar at the bottom (or sometimes top/sides) of the desktop screen in Windows. It serves several key purposes:
Start Button/Menu: Provides access to all applications, settings, power options (shutdown, restart), and more.
Search Bar/Icon: Allows you to quickly search for files, applications, and information on the web.
Pinned Applications: Icons of frequently used applications for quick launch.
Running Applications: Icons of currently open applications, often indicated by an underline or highlight. Clicking these switches between applications.
System Tray/Notification Area: Contains icons for system utilities (e.g., volume, network, battery), background applications, and notifications.
Clock and Calendar: Displays the current time and date.
2.3.2 Icons & Shortcuts
Icons: Small graphical representations of applications, files, folders, or functions. Clicking an icon typically opens or activates the associated item.
- Shortcuts: Special icons that point to the original location of a file, folder, or application. They are identifiable by a small arrow overlay on their icon. Shortcuts save space on your desktop and provide quick access without duplicating the actual file. Deleting a shortcut does NOT delete the original file.
2.3.3 Running an Application
There are several ways to run an application:
From the Start Menu: Click the Start button, then navigate through the list of applications and click on the desired one.
Using a Desktop Shortcut: Double-click the application’s shortcut icon on the desktop.
From the Taskbar: Click on the application’s icon pinned to the taskbar.
Using the Search Bar: Type the name of the application in the search bar and press Enter or click on the search result.
From File Explorer: Navigate to the folder where the application’s executable file (.exe in Windows) is located and double-click it.
2.4 Operating System Simple Setting
2.4.1 Using Mouse and Changing its Properties
The mouse is a primary input device. You can customize its behavior to suit your preferences.
Access Mouse Settings:
Windows 10/11: Go to
Settings > Bluetooth & devices > Mouse.Older Windows: Go to
Control Panel > Mouse.
Common Properties to Change:
Primary Button: Switch primary and secondary buttons for left-handed users.
Double-click Speed: Adjust how fast you need to double-click for an action to register.
Scroll Wheel Settings: Configure how many lines the scroll wheel moves at a time.
Pointer Options: Change pointer speed, enable pointer trails, or hide pointer while typing.
Pointers: Change the appearance of the mouse pointer (e.g., arrow, hand).
2.4.2 Changing System Date and Time
Ensuring your system’s date and time are correct is important for many applications and services.
Access Date & Time Settings:
Windows 10/11: Right-click on the date/time in the taskbar and select
Adjust date and time, or go toSettings > Time & language > Date & time.Older Windows: Double-click the clock in the taskbar or go to
Control Panel > Date and Time.
Options:
Set time automatically: (Recommended) Synchronizes with an internet time server.
Set time zone automatically: Detects your time zone.
Manual Adjustment: Turn off automatic settings to manually change date, time, and time zone.
2.4.3 Changing Display Properties
Display settings allow you to customize how things look on your screen.
Access Display Settings:
Windows 10/11: Right-click on an empty area of the desktop and select
Display settings, or go toSettings > System > Display.Older Windows: Right-click on the desktop and select
Screen resolutionorPersonalize.
Common Properties:
Resolution: Changes the clarity of text and images. Higher resolution means more content can fit on the screen, but things might appear smaller.
Orientation: Switch between landscape and portrait.
Multiple Displays: Configure settings if you have more than one monitor.
Scale and layout: Adjust the size of text, apps, and other items.
Brightness: Adjust screen brightness.
Night light/Color temperature: Reduces blue light for better sleep.
2.4.4 To Add or Remove Program and Features
Properly adding and removing programs is crucial for system stability and security.
Adding Programs:
Most programs are added by running an installer file (usually
.exeor.msi). Follow the on-screen instructions.For Universal Windows Platform (UWP) apps, use the Microsoft Store.
Removing Programs (Windows): * Windows 10/11: Go to Settings > Apps > Apps & features. Find the program in the list, click on it, and select Uninstall. * Older Windows: Go to Control Panel > Programs > Programs and Features. Select the program from the list and click Uninstall.
**Important:** Always use the official uninstaller. Simply deleting program folders might leave residual files and registry entries, which can clutter your system.2.4.5 Adding, Removing & Sharing Printers
Printers are essential peripherals. Here’s how to manage them.
Adding a Printer (Windows):
Go to
Settings > Bluetooth & devices > Printers & scanners(Windows 10/11) orControl Panel > Devices and Printers(older Windows).Click
Add a printer or scanner.Windows will search for available printers. If found, select it and follow the prompts.
If not found, you might need to manually add it using its IP address or by installing the manufacturer’s drivers.
2.5 File and Folder Management
File and Folder Management is the process of organizing, storing, and accessing data on your computer. An OS provides a file management system, like File Explorer in Windows, to help you with this.
Key Concepts
File: A file is a collection of related data stored under a single name (e.g.,
report.docx,photo.jpg).Folder (or Directory): A folder is a container used to group and organize files and other folders. This hierarchical structure helps you find things easily.
Basic Operations
1. Creating a New Folder:
Right-click on an empty space on the desktop or within a folder.
Select
New > Folder.Type a name for the new folder and press
Enter.
2. Copying and Moving Files/Folders:
Copy: Creates a duplicate of the file or folder in a new location, leaving the original intact.
Select the file/folder, right-click and choose
Copy(or pressCtrl+C).Go to the destination, right-click and choose
Paste(or pressCtrl+V).
Move: Transfers the file or folder to a new location, removing it from the original spot.
Select the file/folder, right-click and choose
Cut(or pressCtrl+X).Go to the destination, right-click and choose
Paste(or pressCtrl+V).
3. Deleting Files/Folders:
Select the file/folder you want to delete.
Press the
Deletekey on your keyboard or right-click and selectDelete.Deleted items are usually sent to the Recycle Bin (Windows) or Trash (macOS), which allows you to restore them if needed. To permanently delete, you must empty the Recycle Bin.
4. Renaming Files/Folders:
Select the file/folder you want to rename.
Press the
F2key or right-click and chooseRename.Type the new name and press
Enter.
2.6 Types of File Extensions
A file extension is a suffix at the end of a filename, separated by a dot (e.g., .docx in report.docx). It indicates the file’s type and tells the operating system which program to use to open it.