Operating System: Definition and Functions

• An Operating System (OS) is a computer's manager, ensuring smooth operation
• An OS controls hardware like the keyboard, mouse, screen, etc.
• The OS starts and properly runs programs.
• It saves, organizes, and manages files such as documents, pictures, and videos.
• The OS enables multitasking
• It protects the computer from viruses and unauthorized access
• Examples of operating systems include Windows, macOS, Linux, Android, and iOS
• Without an OS, the computer or phone would be a lifeless box

Importance of an OS

• An OS manages hardware like the CPU, memory, hard drives, keyboard, and mouse
• It runs applications, enabling programs like games, browsers, or MS Word to start
• It provides a user-friendly interface with icons, buttons, and menus to avoid code typing
• It allows multitasking like watching YouTube, downloading, and chatting
• The OS divides computer resources like RAM and CPU so apps run efficiently
• The OS protects data with security measures like passwords and firewalls
• It helps save, organize, and find files easily
• It detects errors and provides troubleshooting

Basic Components of an OS

• Kernel is the core OS that controls everything, including the CPU, memory, and devices
• Process Management handles how applications run, and manages multitasking
• Memory Management manages the computer's RAM, and decides how much memory an app gets
• A file system helps save, organize, and find files
• Device Drivers are special programs that help the OS communicate with hardware
• User Interface (UI) is the part you interact with
• Security and Access Control protects your data from unauthorized users and viruses
• Input/Output (I/O) System manages how data comes into and goes out of from a computer

OS types based on functionality

• Batch Operating Systems collect process jobs in batches without user interaction, such as occurs with overnight bank transactions
• Time-Sharing (Multitasking) Operating Systems enable multiple users or tasks to run at the same time by sharing CPU time
• Example of a Time-Sharing OS: Windows or macOS because you can browse the internet while listening to music
• Distributed Operating Systems have multiple computers that work together to share resources
• Example of a Distributed OS: Google Drive or Cloud Computing because files are stored on multiple servers
• Real-Time Operating Systems (RTOS) process tasks instantly, with strict timing requirements such as airplane autopilot systems
• Network Operating Systems (NOS) manage devices and users on a network
• Example of a NOS: Windows Server is used in offices to control access to files and printers
• Mobile Operating Systems are designed for mobile devices like smartphones and tablets
• Examples of Mobile Operating Systems: Android and iOS used in Samsung and iPhones for apps, calls, and internet browsing.
• Embedded Operating Systems run on specific devices with limited functions
• Example of an Embedded OS: Smart TV OS or Microwave OS which only run the device efficiently

Core Functions

• Process Management efficiently runs multiple programs and schedules tasks
• Memory Management allocates and manages RAM, using virtual memory if needed
• File System Management organizes, stores, and retrieves files securely
• Device Management controls hardware like printers and USBs using device drivers
• User Interface provides GUI (Windows, macOS) or CLI (Linux, UNIX) for user interaction
• Security and Access Control protects data with authentication, permissions, and firewalls
• Networking manages internet and network connections for communication
• Storage Management controls hard drives, backups, and disk management
• Error Detection & Monitoring tracks system performance and detects issues
• Booting Process loads the OS when the computer starts up

Windows Operating System

• Microsoft is the developer
• Stand-Alone OS is the type
• Target audience is personal computers, businesses, and enterprises
• GUI, with icons, taskbars, and windows makes for an easy user interface
• Examples of popular versions: Windows 10, Windows 11, and Windows Server editions
• NTFS (New Technology File System) is the file system
• There is a built-in firewall, antivirus (Windows Defender), and user account control as security
• Windows supports a wide range of software applications and games
• It allows running multiple applications simultaneously
• Windows OS is used in personal computers, laptops, office environments, gaming, and business systems

Linux Operating System

• Linus Torvalds and the open-source community are the developers
• The type of OS is Stand-Alone, or Network OS in server form
• Developers, businesses, and tech enthusiasts are the target audience
• It is free to use and modify.
• Open Source publicly publishes the source code
• Known for being more secure and less vulnerable to viruses
• CLI primarily uses terminal commands, however GUIs are available
• EXT4 is the most common file system, but Btrfs and XFS are also used.
• Ubuntu, Fedora, Debian, CentOS, and Arch Linux are some of the many distributions
• It is highly customizable according to user needs
• It is excellent for performance and running on servers or low-resource devices
• It is used in servers, programming, embedded systems, and by tech-oriented users

MacOS

• Apple Inc. is the developer
• The type is Stand-Alone OS
• Apple computer users use MacOS (MacBooks, iMacs)
• The GUI is polished and has a clean, minimalist design
• APFS (Apple File System) is the file system
• There are strong security features like Gatekeeper, FileVault, and sandboxing
• There is exclusive access to Apple software, but support for many third-party apps
• Seamless integration with other Apple devices through features like Handoff, iCloud, and Continuity
• Optimized for Apple hardware.
• Used by creative professionals, general consumers, and businesses using Apple products

UNIX Operating System

• Bell Labs (AT&T) is the developer
• The type of OS is multi-user, Network OS
• Businesses, universities, large systems, and servers are the target audience
• There is a CLI used through commands, but graphical interfaces are available
• Strong user access controls, multitasking, and multi-user support provides high security
• UFS (Unix File System) is the file system
• Known for being extremely stable and reliable, especially for servers
• Strong networking features make it ideal for internet-connected systems.
• Used on servers, workstations, and enterprise-level systems

Android OS

• Developed by Google, and based on the Linux kernel
• The type of OS is Embedded OS, Mobile OS.
• Target audience: Smartphones, tablets, smart devices
• Highly customizable by manufacturers and users
• Google Play Store, gives this OS a wide range of apps
• Supports multitasking for mobile applications
• There is increased security that includes Google Play Protect, app permissions, and regular security updates
• Deep integration with Google services: Gmail, Google Maps, Google Assistant
• Use cases: Smartphones, tablets, smartwatches, and other mobile devices

iOS (Apple's mobile OS)

• Apple Inc. is the developer
• The OS is an Embedded and Mobile OS
• Target audience: iPhone, iPad, iPod Touch users
• Touch-based user interface
• App Store is the centralized marketplace for apps.
• There are high levels of security with encrypted data, app review processes, and Face/Touch ID
• Strong ecosystem of other Apple devices like Macs and Apple Watches
• Optimized for Apple hardware providing a smooth user experience.
• Smartphones, tablets, and wearable devices use it

Utility Programs

• Utility programs are software tools which are designed to help manage, maintain, and optimize computer systems that perform specific tasks.

What Utility Programs Do

• File Management Utilities: Tools like File Explorer helps you organize and manage files and folders
• Disk Cleanup Tools: Programs such as Disk Cleanup (Windows) remove unnecessary files to optimize disk space
• Backup Utilities: Programs such as Time Machine (macOS) back up your important data and restore files
• Antivirus and Security Tools protect against malware and ensure system security
• File Compression Tools: Programs such as WinRAR or 7-Zip compress files for easier storage and transfer
• Disk Management Tools manage disk partitions and monitor disk health
• System Monitoring Tools: Tools like Task Manager monitor system performance and running processes.
• System Update Utilities: Software that keeps the system and apps up-to-date with the latest patches
• Uninstaller Utilities: Programs like Revo Uninstaller fully remove unwanted software
• Screen Savers: Decorative programs that activate when the computer is idle, providing security features

Importance of OS in Modern Computing

• Resource Management: Allocates CPU, memory, and storage for smooth operation
• User Interface (UI): Provides interfaces (GUI or CLI) for easy interaction
• Multitasking: Enables running multiple applications at once
• Security: Protects data with authentication and antivirus measures
• Hardware Abstraction: Simplifies interaction with hardware for users and apps
• Software Platform: Allows applications to run on different devices
• Networking: Manages connections and data transfer over networks
• Data Management: Organizes files and ensures fast access
• Stability: Ensures system reliability and prevents crashes

Future OS

• AI-Powered OS: OS use AI to predict user needs and automate tasks
• Cloud-Based OS: OS like Chrome OS can run on the cloud for easy access across devices
• Edge Computing: OS can process data closer to devices for faster performance
• Cross-Platform Integration: Seamless experience across smartphones, PCs, and smart devices
• Quantum Computing: OS supporting quantum hardware for faster processing
• AR/VR OS: OS are designed for immersive virtual or augmented environments
• Enhanced Security: Advanced security with biometrics, encryption, and privacy controls
• Self-Healing OS: OS detect and fix issues automatically