Recommend Android Setup with Unity

I know this topic is too old and basic according to nowadays, but i am too eager to ask here the in depth understanding of Android Setup with Unity that how it works and how to tackle specific problem when faced with. My Question is about SDK, NDK, JDK and Gradle Build of Unity Generally (with Normal Version of Unity). I am not specific to a device with bla bla android version. So What is the minimum Android SDK (I have no concept of what is build tool for? platform tool for? etc etc) version to be kept for normal Android Builds (Gradle as default) ? I want to keep SDK size as much optimized(Minimum) as possible to do my work smoothly. Now What is the relation of SDK with JDK or NDK? or Vice versa... Also clearify Minimum API Level and TargetAPI Level in Unity Player Settings with these..Which JDK is better or recommended? As NDK have not make issues with me So I am OK with NDK(as Unity clearly says NDK version accordingly with Unity) but i still have confusion what is NDK? I have too many confusions .. If someone clear my concept about these confusions I will be thankful as i am posting here first time and will be glad to answered politely, concise and to the point.

P.S. I have searched google a lot, unity answers, stackoverflow (tell me any other good place to search for ) So dont tell me to google please answer me here so clearly that i am satisfied.

Thanks in Advance..

 

Sorry If i am posting at wrong forum topic

 

Have you read the manual pages on the topic?
https://docs.unity3d.com/Manual/android-sdksetup.html
https://docs.unity3d.com/Manual/android-gradle-overview.html

And what the NDK is:
https://developer.android.com/ndk/guides

The versions recommended are the versions Unity installs. Any other version would of course then be a not recommended version, though the manual has instructions for doing so regardless. If you need to get really detailed on the pros/cons of different versions, you probably need to ask in the Android forum.

Note, you've got to get better at doing internet searches. I literally just typed "what is android ndk" into Google and got the answer with the first result. This is a required skill for being a software developer.

 

thanks for being helpful with my stupid question (I know it) otherwise no one in any community dare to answer me.. by the way you have ask about google search.. I am skilled with this blessing(Google Search) but cannot read all contents in Google pages so i want just clear point of view (specially linked with unity3d) of these above things..