🧵 Thread vs Process in a nutshell

Understanding the difference between a thread and a process is fundamental to building scalable and efficient systems.

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🔸 What is a Process?

• A process is an independent program in execution.
• It has its own memory space, including code, data, and system resources.
• Starting an application (like a browser or server) creates a new process.

🔸 What is a Thread?

• A thread is a smaller unit of execution within a process.
• All threads in a process share the same memory space and resources, but each has its own call stack and program counter.

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🧠 Analogy

Concept	Analogy
Process	A house
Thread	People living in the house
Shared memory	Rooms and furniture (shared by all)
Stack	Each person's backpack (private)

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🧪 Real-World Example: Web Browser

• Process: Running the Chrome browser.
• Threads:
  • One for the user interface,
  • One for each tab,
  • One for rendering,
  • One for background tasks.

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📊 Key Differences

Feature	Process	Thread
Memory	Has its own memory space	Shares memory with other threads
Overhead	Higher (more OS resources)	Lower (lightweight)
Communication	Requires IPC	Can use shared memory
Fault Isolation	Crash in one doesn’t affect others	Crash in one can crash the whole process
Creation Time	Slower	Faster

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🔧 Why It Matters in System Design

• Threads enable concurrency, improving responsiveness and throughput.
• Processes provide isolation, which is safer for unstable or critical tasks.
• Choose based on:
  • Speed vs. Safety
  • Available memory/CPU
  • Need to share or isolate data

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Understanding threads and processes helps you make better choices when designing everything from web servers to distributed systems.