How does Kotlin coroutines scheduler decide thread execution?

Coroutine execution is managed by dispatchers that schedule work on thread pools or event loops.

Kotlin coroutines do not run on their own threads. Instead, Dispatchers assign execution to thread pools. Dispatchers.IO uses a shared pool optimized for blocking operations, Dispatchers.Default uses CPU-bound threads, and Dispatchers.Main uses UI thread event loops. Suspension points allow coroutines to release threads and resume later, enabling thousands of concurrent tasks on limited threads.