What is the difference between a coroutine, a Task and a Future in asyncio?

Short answer

A coroutine is a description of asynchronous work that does not run until it is awaited or scheduled, a Task wraps a coroutine and schedules it to run concurrently on the loop, and a Future is a low-level object representing a result that will be completed later (a Task is a subtype of it).

Explanation

await coro() runs the coroutine sequentially, whereas asyncio.create_task(coro()) starts running it in the background immediately. Keep a reference to the Task; the loop keeps only a weak reference, so the task may be garbage-collected before it completes, and exceptions in tasks nobody awaits get lost. The best way to manage task lifecycles is TaskGroup.

Code example

import asyncio

background_tasks: set[asyncio.Task] = set()

def fire_and_forget(coro) -> None:
    task = asyncio.create_task(coro)
    background_tasks.add(task)  # Prevents the task from being collected too early
    task.add_done_callback(background_tasks.discard)

Common mistakes

• Calling create_task without keeping the reference, so the task or its errors vanish.
• Awaiting tasks one after another right after creating them, which cancels concurrency.

Follow-up questions

• What is an event loop and what is the role of a coroutine in asyncio?

Sources

• Python documentation — asyncio.create_task