Introduction to Operating Systems

Study Notes

Introduction to Operating Systems

An operating system (OS) is system software that manages computer hardware and software resources.
It acts as an intermediary between a user and the computer hardware.
It provides a platform for running other software applications.
Key functions include process management, memory management, file system management, input/output (I/O) management, and security.

Process Management

The OS manages the execution of programs, referred to as processes.
This includes tasks like creating, scheduling, and terminating processes.
It handles resource allocation to each process, such as CPU time and memory.
Processes can be in various states: running, ready, waiting, or terminated.
Scheduling algorithms decide which process gets the CPU time.

Memory Management

Memory management involves allocating and deallocating memory space for processes.
This includes virtual memory, which extends the amount of memory available.
Techniques like paging and segmentation are used to manage memory effectively.
Memory protection mechanisms prevent one process from accessing another's memory.

File System Management

File systems organize and manage files on storage devices.
Different file systems use various structures to store and locate files.
This includes metadata for file information.
Key operations include creating, reading, writing, and deleting files.

Input/Output (I/O) Management

The OS controls how the computer interacts with peripherals.
I/O devices are managed by device drivers.
Device drivers abstract the complexities of each device and provide a standard interface.
The OS handles the transfer of data between processes and devices.

Security

The OS provides security features to protect the system from unauthorized access.
This includes authentication, access control, and encryption.
User accounts and permissions manage access to system resources.
Protecting the system from malware and security threats.

Types of Operating Systems

Batch operating systems process jobs in batches.
Time-sharing operating systems allow multiple users to share the system's resources.
Real-time operating systems respond to events within specific time constraints.
Embedded systems operate in specialized devices.
Distributed operating systems manage multiple computers working together.

Kernel

The kernel is the core of the operating system.
It is responsible for managing the most fundamental aspects of the system.
It interacts directly with the hardware.
The kernel controls the allocation of CPU time, memory, and other essential resources.

System Calls

System calls are the interface between applications and the OS.
They allow applications to request services from the kernel.
Examples include reading from a file or creating a new process.

User Interface (UI)

The user interface provides a way for users to interact with the OS.
Graphical User Interfaces (GUIs) are common.
Command-line interfaces (CLIs) offer another way to interact.

Multitasking and Multiprocessing

Multitasking allows multiple programs to run concurrently.
Multiprocessing involves using multiple processors to perform tasks concurrently.
These systems improve efficiency and responsiveness to user tasks.

Device Drivers

Device drivers are software that enable the OS to interact with specific hardware devices.
Each device type requires a specific driver.
Drivers translate requests from the OS into signals understood by the hardware.

Virtualization

Virtualization is the creation of virtual versions of resources and systems.
This includes virtual machines and containers.
It allows multiple operating systems and applications to run on a single physical machine concurrently.

Description

This quiz covers the fundamental concepts of operating systems, including their role and key functions like process and memory management. You will explore how operating systems interact with hardware and manage resources for software applications. Test your understanding of process states, scheduling algorithms, and memory allocation techniques.