Introduction to Operating Systems
An Operating System (OS) is system software that acts as an intermediary
between the hardware of a computer and the user. It provides a user interface,
manages resources, and ensures that applications function efficiently. Examples
include Windows, Linux, macOS, and Android.
Functions of an Operating System
1. Resource Management: Manages CPU, memory, and I/O devices to
optimize overall performance.
2. Process Management: Schedules and controls the execution of processes,
ensuring that tasks are completed efficiently and without conflicts.
3. File System Management: Organizes and stores data in a structured
manner, allowing users to retrieve and manipulate files easily.
4. Security and Access Control: Protects sensitive data and system resources
from unauthorized access and external threats.
5. Error Detection and Handling: Monitors the system for errors and takes
corrective actions to maintain stability.
Additional Features of Modern Operating Systems
Graphical User Interface (GUI): Simplifies interaction with the system
through visual elements like icons and windows.
Networking: Enables communication between devices and supports
internet connectivity.
Device Management: Provides drivers and tools for managing peripherals
like printers and external storage devices.
Virtualization: Allows multiple operating systems to run on a single physical
machine.
, Types of Operating Systems
1. Batch Operating System
Executes batches of jobs without user interaction.
Jobs are collected, grouped based on similarities, and executed sequentially
by the system.
Common in early computers where manual job scheduling was impractical.
Advantages: Simple to implement; reduces idle time.
Disadvantages: Lack of user interaction; debugging errors is challenging.
2. Time-Sharing Operating System
Supports multiple users simultaneously by allocating small time slices to
each task.
Ensures quick response times, creating an interactive environment.
Example: UNIX.
Advantages: Efficient CPU utilization; supports multiple terminals.
Disadvantages: Complex to manage; may experience system overload.
3. Distributed Operating System
Manages a network of independent computers and makes them appear as
a single system.
Promotes resource sharing, load balancing, and fault tolerance.
Examples: Amoeba, Plan 9.
Advantages: High reliability; scalability; efficient resource use.
Disadvantages: Complex communication; security concerns.
4. Real-Time Operating System (RTOS)
Ensures tasks are completed within predefined time constraints, often
critical for system functionality.
Used in embedded systems, robotics, and industrial applications.
Examples: VxWorks, FreeRTOS.
Types of RTOS:
o Hard Real-Time: Tasks must meet strict deadlines.
o Soft Real-Time: Some delay is tolerable, but performance may
degrade.