What is the difference between asynchronous and parallel execution?

Asynchrony allows tasks to be performed interleaved, without blocking the main execution thread while waiting for resource-intensive operations (e.g., I/O) to complete. One task can pause, giving way to another, and then resume execution.

Parallelism involves the simultaneous execution of multiple tasks, usually on different processor cores. This is achieved using processes or threads.

Characteristic	Asynchrony	Parallelism
Execution	Interleaved task execution	Simultaneous task execution
Resources	One thread/process (most often)	Multiple threads/processes
Goal	Efficient use of waiting time (I/O)	Speeding up CPU-bound tasks
Mechanisms	asyncio, await	threading, multiprocessing

# Example of asynchrony
import asyncio

async def task1():
    print("Task 1 is running")
    await asyncio.sleep(1) # Simulate a long operation
    print("Task 1 completed")

async def task2():
    print("Task 2 is running")
    await asyncio.sleep(1) # Simulate a long operation
    print("Task 2 completed")

async def main():
    await asyncio.gather(task1(), task2()) # Run tasks asynchronously

if __name__ == "__main__":
    asyncio.run(main())

# Example of parallelism with threads
import threading
import time

def task1():
    print("Task 1 is running")
    time.sleep(1) # Simulate a long operation
    print("Task 1 completed")

def task2():
    print("Task 2 is running")
    time.sleep(1) # Simulate a long operation
    print("Task 2 completed")

thread1 = threading.Thread(target=task1)
thread2 = threading.Thread(target=task2)

thread1.start()
thread2.start()

thread1.join()
thread2.join()

print("All tasks completed")