Suspending functions are suspending computations in the shape of a function. A suspending function can be easily identified because of the modifier suspend. For example:

suspend fun greetAfter(name: String, delayMillis: Long) {
    delay(delayMillis)
    println("Hello, $name")
}

In the previous example, the execution of greetAfter() will be suspended when delay() is called – delay() is a suspending function itself, suspending the execution for a give duration. Once delay() has been completed, greetAfter() will resume its execution normally. And while greetAfter() is suspended, the thread of execution may be used to do other computations.