Android build SDK version, target SDK and minimum SDK

[mentalmushroom]

In the build settings of the Qt android project there is the Android build SDK parameter:
Знімок екрана 2017-02-24 08.49.34.jpg

I am wondering what should I choose there. For instance, if I select "android-21", does it mean that the application requires API level 21 or higher?


Android manifest also contains the Minimum required SDK and Target SDK parameters:
Знімок екрана 2017-02-24 08.49.45.jpg

Should the minimum required SDK or the target SDK be the same as Build SDK?