Kotlin Gradle plugin: apiVersion vs languageVersion

Question

Kotlin Gradle plugin contains compileKotlin task which can be configured by apiVersion and languageVersion parameters (doc):

compileKotlin {
    kotlinOptions {
        freeCompilerArgs = ['-Xjsr305=strict']
        jvmTarget = '1.8'
        languageVersion = '1.1'
        apiVersion = '1.1'
    }
}

Both parameters are used for compatibility with older Kotlin versions. Could somebody explain what is the difference between them? And what are use cases using each of them?

Answer 1

apiVersion: Allow to use declarations only from the specified version of bundled libraries

languageVersion: Provide source compatibility with specified language version

You can see full documentation here: https://kotlinlang.org/docs/reference/using-gradle.html

and this reference: https://kotlinlang.org/docs/reference/building-mpp-with-gradle.html