DOC-20240921-WA0003_240921_155154.pdf

FUNDAMENTALS OF INFORMATION COMMUNICATION TECHNOLOGY (ICT) UNIT I Aditya Rajesh More Operating System An operating system (OS) is a critical software layer that manages a computer's hardware and software resources. It provides a stable environment for applications to run and acts as an inter...

FUNDAMENTALS OF INFORMATION COMMUNICATION TECHNOLOGY (ICT) UNIT I Aditya Rajesh More Operating System An operating system (OS) is a critical software layer that manages a computer's hardware and software resources. It provides a stable environment for applications to run and acts as an intermediary between the user and the hardware. The OS ensures that different programs and users can effectively share the system resources without interfering with each other. It provides a stable and consistent environment for applications to run, offering essential services such as process management, memory management, file system management, device management, and security. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 2 Key Functions of an Operating System 1. Process Management: Process Scheduling: Manages the execution of processes by determining the order and duration for which processes run. Process Creation and Termination: Handles the lifecycle of processes, including their creation, execution, and termination. Concurrency Control: Ensures efficient and safe execution of multiple processes simultaneously, often using techniques like multitasking and multithreading. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 3 Key Functions of an Operating System 2. Memory Management: Memory Allocation: Allocates and deallocates memory to processes as needed. Memory Protection: Prevents processes from accessing each other’s memory, ensuring data integrity and security. 3. File System Management: File Organization: Manages the structure and storage of files on various storage devices. Access Control: Enforces permissions and access controls to ensure that only authorized users can access or modify files. Storage Management: Coordinates the storage and retrieval of data across different storage media. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 4 Key Functions of an Operating System 4. Device Management: Device Drivers: Provides a standardized interface for software to interact with hardware devices. I/O Operations: Manages input and output operations to ensure data is correctly transferred between the hardware and processes. Interrupt Handling: Responds to hardware interrupts to process events and ensure smooth device operation. 5. Security and Protection: Authentication: Verifies user identities to control access to the system. Authorization: Determines user permissions and access levels to various resources. Data Encryption: Protects data from unauthorized access and ensures secure communication. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 5 Key Functions of an Operating System 6. User Interface: Command-Line Interface (CLI): Allows users to interact with the OS using text commands. Graphical User Interface (GUI): Provides a visual interface with icons, windows, and menus for user interaction. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 6 What is Kernel? A kernel is the core part of an operating system. It acts as a bridge between software applications and the hardware of a computer. The kernel manages system resources, such as the CPU, memory, and devices, ensuring everything works together smoothly and efficiently. It handles tasks like running programs, accessing files, and connecting to devices like printers and keyboards. On most systems, the kernel is one of the first programs loaded on startup (after the bootloader). It handles the rest of startup as well as memory, peripherals, and input/output (I/O) requests from software, translating them into data-processing instructions for the central processing unit. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 7 What is Kernel? Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 8 What is Booting? When a computer system is started, there is a mechanism in the system that loads the operating system from the secondary storage into the main memory, or RAM, of the system. This is called the booting process of the system. Types of Booting There are two types of booting depending on the number of operating systems installed on the machine/computer, i.e. 1. Cold or Hard Booting 2. Soft or Warm Booting Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 9 What is Booting? 1. Cold or Hard Booting A state in which a computer is switched on from being switched off is referred to as cold booting. Powering on a computer that has been turned off completely is usually called a cold boot. In this procedure, the system undergoes a complete power-on self-test (POST) that initializes hardware devices and loads operating systems from a storage medium into random-access memory (RAM). 2. Soft or Warm Booting ​Soft boot or restart method Warm Booting, also called soft boots or restarts, reboots a computer system without shutting it down entirely. This technique is usually started by an operating system restart command or by pressing an appropriate key combination. Warm reboots do skip some of the hardware initialization processes that are done on cold booting. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 10 What is Power on Self Test (POST) Booting? Power on Self Test booting is a part of the booting cycle in a computer system. The POST is the very first diagnostic routine that the installed hardware components undergo every time you power up your computer to assure the presence and functionality of the devices. The POST tests the status of many hardware components, including the CPU, memory, storage devices, and other peripherals. It watches for problems that may prevent booting. In case of a malfunction, the POST usually displays some error message or beeps in a pattern that indicates where the problem lies. If it succeeds, the computer starts loading the operating system and other necessary software for normal running. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 11 Steps In the Booting Process Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 12 Steps In the Booting Process 1. BIOS is Loaded BIOS (Basic Input/Output System): Firmware stored on a chip on the motherboard. Initialization: When the computer is powered on, the CPU initializes the BIOS. The BIOS provides the first instructions the CPU executes. Purpose: The BIOS initializes and identifies system devices such as the video display card, keyboard, mouse, hard disk, optical disk, and other hardware. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 13 Steps In the Booting Process 2. Power-On Self Test (POST) Purpose: To check the hardware components and ensure there are no errors before loading the operating system. Components Tested: RAM, CPU, storage devices, keyboard, and other peripherals. Indicators: If POST completes successfully, it usually emits a single beep. Multiple beeps indicate errors, and the number and pattern of beeps can help diagnose the issue. Error Messages: If there is a failure, the BIOS might display error messages on the screen or through beep codes. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 14 Steps In the Booting Process 3. Operating System is Loaded Bootloader: A small program that loads the operating system. Process: The BIOS looks at the boot order set in the BIOS configuration (usually accessed via a key press like F2, DEL, or ESC during POST) to find the device to boot from. Execution: The BIOS transfers control to the bootloader found on the designated boot device (HDD, SSD, CD/DVD, USB drive). Kernel Loading: The kernel is the core part of the operating system. Process: The bootloader loads the kernel into memory and starts it. Outcome: The kernel takes over the system, continuing the boot process. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 15 Steps In the Booting Process 4. System Configuration is Accomplished Kernel Initialization: Hardware Initialization: The kernel detects and initializes all system hardware components, ensuring they are ready for use. Memory Management: The kernel sets up the memory management system, configuring virtual memory and memory allocation. Driver Loading: The kernel loads drivers necessary for the hardware components. Filesystem Mounting: Root Filesystem: The kernel mounts the root filesystem, which contains the core operating system files. Additional Filesystems: Other filesystems (e.g., user data partitions) are also mounted as configured. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 16 Steps In the Booting Process 5. System Utilities are Loaded Initialization Scripts: Scripts that run during the boot process to configure the system and start services. Systemd/Init: Modern systems use systemd or init to handle this. These tools manage the startup of all system services and daemons. Services and Daemons: Network Services: These might include DHCP clients, network managers, and other networking tools. System Logging: Services like syslog or journald start to handle system logs. Other Services: Other necessary background services such as sound servers, and display managers (for graphical interfaces) are started. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 17 Steps In the Booting Process 6. User is Authenticated Login Prompt: CLI (Command Line Interface): In text-based systems, a login prompt appears asking for the username and password. GUI (Graphical User Interface): In graphical systems, a login screen appears where the user can enter their credentials. Authentication: Credentials Verification: The system verifies the entered username and password against stored credentials. Security Checks: Additional security checks (such as multi-factor authentication) may also occur. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 18 What is File Management in OS? File management in an operating system refers to the set of processes and techniques involved in creating, organizing, accessing, manipulating, and controlling files stored on storage devices such as hard drives, solid-state drives, or network storage. It encompasses a range of tasks and functionalities that ensure efficient handling of files, including their creation, deletion, naming, classification, and protection. It involves managing file metadata, which includes attributes such as file name, file size, creation date, access permissions, ownership, and file type. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 19 Key Components of File System Management File System Structure: Files: The basic unit of storage, representing a collection of data. Directories: Also known as folders, these are containers that hold files and other directories, forming a hierarchical structure. Paths: The route through the directory structure to a file or directory, often represented as strings (e.g., /home/user/document.txt in Unix-like systems or C:\Users\User\Documents\document.txt in Windows). File Types: Regular Files: Store user data, such as text, images, videos, and applications. Directories: Special files that list other files. Special Files: Used for device input/output (e.g., /dev/sda1 for a hard disk partition). Links: Shortcuts or pointers to other files (hard links and symbolic links). Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 20 Functions of File System Management File Creation and Deletion: Creation: The OS provides system calls to create new files and directories, allocating space on the storage device and updating the directory structure. Deletion: When a file is deleted, the OS removes its directory entry and marks its storage space as available for reuse. File Organization: Allocation Methods: The OS uses various methods to allocate space for files, including contiguous allocation, linked allocation, and indexed allocation. Metadata Management: Each file has associated metadata (e.g., file size, creation date, permissions) that the OS maintains in structures like inodes (Unix) or MFT entries (Windows NTFS). Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 21 Functions of File System Management File Access and Manipulation: Read/Write Operations: The OS provides system calls for reading from and writing to files, handling the transfer of data between memory and storage. File Permissions: The OS enforces access control using file permissions, ensuring only authorized users and processes can access or modify files. Locking Mechanisms: To prevent concurrent access issues, the OS can lock files, ensuring that only one process can modify a file at a time. Directory Management: Navigation: The OS allows users and applications to navigate the directory structure to locate files. Directory Operations: Includes creating, deleting, and renaming directories, as well as listing directory contents. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 22 Types of File Systems 1. FAT (File Allocation Table) Variants: FAT12, FAT16, FAT32, exFAT Usage: Older Windows systems, removable media like USB drives, memory cards. Features: FAT12/16/32: Simple structure, widespread compatibility. exFAT: Designed for flash drives, supports larger files and volumes than FAT32. Limitations: Inefficient for large volumes, lacks modern features like journaling, security, and compression. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 23 Types of File Systems 2. NTFS (New Technology File System) Usage: Modern Windows systems (starting from Windows NT to current versions). Features: Large File and Volume Support: Handles large files and disk volumes efficiently. Advanced Permissions: Supports detailed file permissions and access control lists (ACLs). Journaling: Keeps track of changes not yet committed to the main part of the file system to enhance reliability. Encryption and Compression: Built-in support for file encryption (EFS) and compression. Quotas: Allows administrators to set disk space limits for users. Limitations: Compatibility with non-Windows systems can be limited. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 24 Types of File Systems 3. ext (Extended File System) Variants: ext2, ext3, ext4 Usage: Linux systems. Features: ext2: No journaling, but reliable and still used for some specific applications. ext3: Adds journaling to improve reliability and recovery. ext4: Enhanced performance, supports larger volumes and files, backward compatible with ext3. Limitations: Ext3 and ext4 do not support online defragmentation as efficiently as some other file systems. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 25 Types of File Systems 4. HFS+ (Hierarchical File System Plus) Usage: Older macOS systems (before macOS High Sierra). Features: Large File and Volume Support: Handles large files and volumes. Metadata: Extensive metadata support for file attributes. Journaling: Enhances reliability by keeping track of changes. Limitations: Performance and reliability have been surpassed by newer file systems like APFS. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 26 Types of File Systems 5. APFS (Apple File System) Usage: Modern macOS systems (starting with macOS High Sierra), iOS, watchOS, tvOS. Features: Optimized for Flash Storage: Designed to work efficiently with SSDs and flash drives. Snapshotting: Allows creation of snapshots for backups and restores. Encryption: Strong encryption support, with per-file encryption and multi-key encryption. Space Sharing: Allows multiple file systems to share the same physical space. Limitations: Still evolving and may have compatibility issues with older macOS applications. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 27 What is a Software? In a computer system, the software is basically a set of instructions or commands that tell a computer what to do. In other words, the software is a computer program that provides a set of instructions to execute a user’s commands and tell the computer what to do. For example like MS-Word, MS-Excel, PowerPoint, etc. Software can be broadly categorized into two main types: System Software and Application Software. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 28 Types of Software System Software Definition: System software serves as the interface between the hardware and the user applications. It manages the hardware components and provides a platform for running application software. Types of System Software: Operating Systems (OS): Definition: Software that manages computer hardware, software resources, and provides common services for computer programs. Examples: Windows, macOS, Linux, Unix, Android, iOS. Functions: Process management, memory management, file system management, device management, user interface. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 29 Types of Software Device Drivers: Definition: Programs that control a particular type of device that is attached to a computer. Examples: Printer drivers, graphics drivers, network drivers. Functions: Facilitate communication between the OS and hardware devices, ensuring that hardware functions properly. Firmware: Definition: Low-level software programmed into read-only memory that provides control for the device's specific hardware. Examples: BIOS, UEFI, embedded systems firmware. Functions: Initialize and manage hardware components, provide a platform for higher-level software. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 30 Types of Software Application Software Definition: Application software is designed to help users perform specific tasks. These tasks can range from productivity to entertainment and more. Types of Application Software: Productivity Software: Definition: Software aimed at increasing productivity, such as managing documents, presentations, and spreadsheets. Examples: Microsoft Office (Word, Excel, PowerPoint), Google Workspace (Docs, Sheets, Slides). Functions: Create, edit, and manage documents, spreadsheets, presentations, and other office-related tasks Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 31 Types of Software Multimedia Software: Definition: Applications for creating and managing multimedia content. Examples: Adobe Creative Suite (Photoshop, Illustrator, Premiere Pro), VLC Media Player, iTunes. Functions: Create, edit, and play audio, video, and graphics. Web Browsers: Definition: Software used to access and navigate the internet. Examples: Google Chrome, Mozilla Firefox, Microsoft Edge, Safari. Functions: Browse web pages, download files, run web applications, and access online services. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 32 Difference between System software and Application software System Software Application Software Application Software is a type of software that is System software is a set of computer programs that is mainly developed to perform a specific task as per the designed to manage system resources. user's request. It acts as an interface between the Application It acts as an interface between the end-user and System Software and Computer hardware. Software. It is a general-purpose software. It is a specific-purpose software. System software is usually installed on the computer Application Software is usually installed on the system system at the time of OS installation. as per the requirement of the user. This software runs independently and works as a This software is not capable of running independently, platform for working application software. which means they need system software to work on. These are usually written in low-level languages such These are usually written in a high-level language such as Assembly language. as C, C++, Java, etc. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 33 Difference between System software and Application software System Software Application Software System software work on the background, hence user Application software work on user-interface, hence user don't directly interact with them. directly interact with them. A system software starts running as we turn on our Application software runs as per user request. It means computer system and stops when the system is turned when we launch them, then only they start and stop off. when we close them. The development of System software is complicated and Development of Application software is comparatively takes more time compared to application software easier and takes less time than system software. A computer system can always run without application A computer system can't run without system software. software. The working of system software is automated and starts The working of application software is manual, which functioning automatically after starting the computer means the user needs to start using it. system. Examples of System Software are Operating systems, Examples of Application Software are Web browsers, Compiler, Assembler, Device drivers, etc. MS office, Graphic design software, etc. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 34 Freewares Freeware refers to software that is available to users at no cost. Users can download, install, and use freeware without any monetary exchange, though there may be some limitations compared to paid versions. Freeware is often created by individual developers or small companies who wish to distribute their software to a wide audience without financial barriers. While the software is free, developers sometimes include optional features or solicit donations to support further development. Examples of popular freeware include programs like VLC Media Player, which offers robust media playback capabilities, and GIMP, a powerful image editing tool. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 35 Shareware Shareware is a type of software that is distributed for free on a trial basis, with the intent that users will pay for it after the trial period or for additional features. This model allows users to evaluate the software before committing to a purchase, providing a risk-free way to try out the software’s capabilities. Shareware often comes with some limitations, such as reduced functionality, a usage time limit, or reminders to purchase the full version. This model is beneficial for both users and developers; users get the chance to explore the software's features before buying, and developers can reach a broad audience, potentially increasing their sales. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 36 Shareware Key characteristics of shareware include: Free Trial: Users can try the software for free before deciding to purchase it. Limited Features or Time: The free version may have limited functionality or be available for a limited period. Encouragement to Purchase: After the trial period or for full functionality, users are encouraged to purchase a license. Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 37 Summary of Freeware and Open Source Software Fundamentals of Information Communication Technology (ICT) Unit I- by Aditya More 38