minSDK dictates if an app will work on your old device or not. Depending on how you build you app, the minSDK can be 14 (Android 4), 19 (Android 4) or 21 (Android 5). Google Play services do not support Android versions below SDK 19
targetSDK is simply the way for the developer to say “my app works best with this SDK version and I want to use the new features”
As long as your device has an higher version than the app’s minSDK the app will work. For example, if the app’s minSDK is 26 (Android 8), the app will only run on devices with Android 8 or higher.
this is about the targetSDK not the minSDK
minSDK dictates if an app will work on your old device or not. Depending on how you build you app, the minSDK can be 14 (Android 4), 19 (Android 4) or 21 (Android 5). Google Play services do not support Android versions below SDK 19
targetSDK is simply the way for the developer to say “my app works best with this SDK version and I want to use the new features”
As long as your device has an higher version than the app’s minSDK the app will work. For example, if the app’s minSDK is 26 (Android 8), the app will only run on devices with Android 8 or higher.