Android Studio の設定で「バージョン」の記述してるとこありすぎね?

あちこちに, 似たようなバージョン的な記述あります Android Studio.

build_gradle

Project_Structure

プロジェクトの改修や移動などで変更しなければならないとき

どこを編集したらいいのか.

いや, 同期されるのか

いや, 優先順位が決まっているのか

どうなのかよくわかりません.

項目もたくさんあります.

どんなのあるか並べてみます.

Default Settings

[Quick Start]-[Configure]-[Project Default]-[Settings]
[File]-[Other Settings]-[Default Settings]

+ Compiler
  + Java Compiler
    + Project byte code version(JDK Default(1.7))

Preferences

Default Project Structure

[Quick Start]-[Configure]-[Project Default]-[Project Structure]
[File]-[Other Settings]-[Default Project Structure]

+ Project Settings
  + Project
    + Project SDK(Android API 19 Platform)
    + Project language level(7.0 - Diamonds, ARM, multi-catch etc.)
+ Platform Settings
  + SDKs
    + Build target(Android 2.3.3)
  + JDK location(/Library/Java/JavaVirtualMachines/jdk1.7.0_51.jdk/Contents/Home)

Project_Structure
Project_Structure 2

Project Structure

[File]-[Project Structure]

+ Project Settings
  + Modules
    + Properties
      + Android Plugin Version(0.9.1)
      + Compile Sdk Version(19)
      + Build Tools Version(19.0.3)
    + Dependencies
      + (com.android.support:support-v4:19.0.0)
      + (com.android.support:appcompat-v7:19.0.0)
      + (com.google.android.gms:play-service:+)
+ Platform Settings
  + Android SDK
    + JDK location(/Library/Java/JavaVirtualMachines/jdk1.7.0_51.jdk/Contents/Home)

Project_Structure

AndroidManifest.xml

<uses-sdk
    android:minSdkVersion="9"
    android:targetSdkVersion="19" />

build.gradle

buildscript {
    dependencies {
        classpath 'com.android.tools.build:gradle:0.9.1'
    }
}
 
android {
    compileSdkVersion 19
    buildToolsVersion '19.0.3'
    defaultConfig {
        minSdkVersion 9
        targetSdkVersion 19
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_7
        targetCompatibility JavaVersion.VERSION_1_7
    }
}
 
dependencies {
    compile 'com.android.support:support-v4:19.0.0'
    compile 'com.android.support:appcompat-v7:19.0.0'
    compile 'com.google.android.gms:play-services:+'
}