OperatingSystemLecture-notebook

Study note

An Operating System (OS) is the core system software that manages computer hardware and provides services to application programs. It acts as an interface between the user, applications, and hardware.

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1️⃣ What an Operating System Does

🔹 Resource Management

• CPU: Process scheduling, multitasking
• Memory: Allocation, virtual memory, paging
• Storage: File systems, disk management
• I/O Devices: Keyboard, mouse, printer, network

🔹 Process & Thread Management

• Process creation and termination
• Inter-process communication (IPC)
• Context switching

🔹 File System Management

• Files & directories
• Access permissions
• Storage abstraction

🔹 Security & Protection

• User authentication
• Access control
• Process isolation

🔹 User Interface

• CLI (Command Line Interface) – e.g., Bash
• GUI (Graphical User Interface) – e.g., Windows Desktop

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2️⃣ Main Components of an OS

Component	Description
Kernel	Core part managing hardware and system calls
Shell	Interface for users to interact with OS
File System	Organizes and stores data
Device Drivers	Control hardware devices
System Libraries	Provide APIs for applications

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3️⃣ Types of Operating Systems

🔸 Batch OS

• Executes jobs in batches
• No user interaction

🔸 Time-Sharing OS

• Multiple users/processes share CPU
• Example: UNIX

🔸 Real-Time OS (RTOS)

• Deterministic response time
• Used in robotics, embedded systems (relevant if you're learning robot programming)

🔸 Distributed OS

• Multiple computers act as one system

🔸 Embedded OS

• Specialized OS for devices
• Example: FreeRTOS, VxWorks

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4️⃣ Common Operating Systems

OS	Used For
Windows	Personal & enterprise computing
Linux	Servers, AI, cloud, embedded
macOS	Apple devices
Android	Mobile & embedded
iOS	Apple mobile devices
RTOS	Robotics, automotive, IoT

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5️⃣ Kernel Architectures

Architecture	특징
Monolithic	Fast, all services in kernel (Linux)
Microkernel	Minimal kernel, high stability
Hybrid	Mix of both (Windows, macOS)

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6️⃣ Why OS Matters (Computer Science Perspective)

• Enables abstraction of hardware
• Ensures efficient scheduling
• Provides security boundaries
• Critical for systems programming, AI servers, robotics

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7️⃣ If You Want to Go Deeper

Given your interest in robot programming & system design, useful next topics:

• Process vs Thread
• Scheduling algorithms (FCFS, Round Robin)
• Virtual memory
• Linux kernel basics
• RTOS vs Linux comparison

If you'd like, I can:

• Explain OS from a robotics perspective
• Give a Linux OS learning roadmap
• Compare RTOS vs Linux vs ROS
• Provide OS interview-level explanations

Just tell me 👍