What is the difference between launch and async/await in Kotlin?

launch starts a coroutine that performs work and does not return a result. It is intended for executing tasks that do not require blocking to wait for completion.

async starts a coroutine that performs work and returns a result of type Deferred<T>. To get the result, await() is used, which suspends the current coroutine until the asynchronous task completes. async/await are used when you need to obtain a result from an asynchronous operation.

Example usage:

// launch - without a return value
fun doSomethingAsync() = GlobalScope.launch {
    delay(1000)
    println("Work completed")
}

// async/await - with a return value
suspend fun calculateSomethingAsync(): Int = GlobalScope.async {
    delay(1000)
    42
}.await()

suspend fun main() {
    doSomethingAsync()

    val result = calculateSomethingAsync()
    println("Result: $result")
}

Summary table of differences:

Feature	launch	async/await
Return type	Job	Deferred<T>
Waiting	Does not block (fire and forget)	Requires await() for blocking wait for result
Usage	For launching tasks that do not require returning a result	For launching tasks whose result is needed for further logic
Error handling	Through CoroutineExceptionHandler	Through try-catch block when calling await()