What is the main difference between threads of execution and separate processes in an operating system?

The main difference between threads and separate processes lies in the level of isolation and resource sharing:

• Processes are independent instances of programs with their own address space, memory, and system resources. Processes are isolated from each other, and inter-process communication (IPC) is required for data exchange.

• Threads are execution units within a process that share the same address space and process resources (e.g., memory, open files). Threads are easier to create and switch between but require synchronization for safe access to shared data.

Example in Python using threads and processes:

import threading
import multiprocessing

def worker():
    print("Working")

# Thread
thread = threading.Thread(target=worker)
thread.start()
thread.join()

# Process
process = multiprocessing.Process(target=worker)
process.start()
process.join()

Here, it is visible that threads operate within a single process, while processes are separate instances.