# coroutine

CEFR C2 · Noun

Source: https://englishreference.com/word/coroutine
Updated: 2026-07-22

## Definition

a part of a computer program that can stop its work and start again later. It is useful for doing many tasks at once without making the computer work too hard.

For teachers: a program component that allows for non-preemptive multitasking by yielding execution to other routines and resuming at the point of suspension. Unlike a standard subroutine, it maintains its state between calls.

## Examples

- The developer used a coroutine to handle the network request in the background.
- By implementing a coroutine, the game engine can process complex physics calculations over several frames without freezing the user interface.
- Modern asynchronous programming often relies on coroutines to manage concurrent operations efficiently, avoiding the high memory overhead associated with spawning multiple operating system threads.

## Usage notes

- Commonly used in the context of asynchronous programming and cooperative multitasking.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.