basics

Operating Systems (OS) - Overview

Definition

An Operating System (OS) is system software that acts as an interface between computer hardware and software applications. Its primary functions include process management, memory management, file system management, device management, and providing a user interface.

How Does an OS Work?

Kernel: The core component responsible for process and memory management, hardware interaction, and more.
Process Management: Manages the execution, scheduling, and termination of processes.
Memory Management: Allocates and deallocates memory for processes and handles virtual memory.
File System Management: Organizes data into files and directories, managing file operations.
Device Management: Controls hardware devices and offers an abstraction layer for applications.
User Interface: Provides graphical or text-based interfaces for user interaction.
Security: Enforces access control, user authentication, and resource protection.
Error Handling: Monitors system events, logs errors, and supports error recovery.
Networking (in modern OSes): Enables communication and internet connectivity.

Operating systems are essential for efficient hardware utilization and user-friendly computing.

Unix

Unix is a family of influential, multiuser, and multitasking operating systems developed at AT&T's Bell Labs in the late 1960s.
Key features:
- Hierarchical file system.
- Command-line interface.
- Modularity and extensibility.
Unix variants include Linux, macOS, BSD, AIX, Solaris, and HP-UX.
Known for stability, security, and its impact on internet infrastructure and software development.

POSIX (Portable Operating System Interface)

POSIX defines standards for maintaining compatibility across operating systems, making it easier to port programs between systems.
For example, in Unix-like systems, it standardizes elements like stdin, stdout, and stderr, streamlining development.
POSIX also provides standards for exit codes, filesystem operations, and command-line utilities, ensuring consistency across platforms.

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Last updated 1 month ago

Operating Systems (OS) - Overview

Definition

How Does an OS Work?

Kernel: The core component responsible for process and memory management, hardware interaction, and more.

Process Management: Manages the execution, scheduling, and termination of processes.

Memory Management: Allocates and deallocates memory for processes and handles virtual memory.

File System Management: Organizes data into files and directories, managing file operations.

Device Management: Controls hardware devices and offers an abstraction layer for applications.

User Interface: Provides graphical or text-based interfaces for user interaction.

Security: Enforces access control, user authentication, and resource protection.

Error Handling: Monitors system events, logs errors, and supports error recovery.

Networking (in modern OSes): Enables communication and internet connectivity.

Operating systems are essential for efficient hardware utilization and user-friendly computing.

Unix

Unix is a family of influential, multiuser, and multitasking operating systems developed at AT&T's Bell Labs in the late 1960s.

Key features:

Hierarchical file system.
Command-line interface.
Modularity and extensibility.

Unix variants include Linux, macOS, BSD, AIX, Solaris, and HP-UX.

Known for stability, security, and its impact on internet infrastructure and software development.

POSIX (Portable Operating System Interface)

POSIX defines standards for maintaining compatibility across operating systems, making it easier to port programs between systems.

For example, in Unix-like systems, it standardizes elements like stdin, stdout, and stderr, streamlining development.

POSIX also provides standards for exit codes, filesystem operations, and command-line utilities, ensuring consistency across platforms.