# Android Gradle (Android) > Build system, dependencies, build types, flavors, signing - 26 interview questions - Junior - [Interview Questions: Android](https://sharpskill.dev/en/technologies/android/interview-questions.md) ## 1. What is Gradle in Android? **Answer** Gradle is Android's official build system. It automates code compilation, dependency management, packaging into APK/AAB, signing, and running tests. Gradle uses scripts (build.gradle) written in Groovy or Kotlin DSL. It's a flexible and powerful tool that replaces older systems like Ant or Maven. ## 2. What's the difference between build.gradle (Project) and build.gradle (Module: app)? **Answer** build.gradle (Project): GLOBAL configuration for all project modules. Defines repositories (Maven, Google), Android Gradle plugin versions, common dependencies. build.gradle (Module: app): SPECIFIC configuration for app module. Defines applicationId, versionCode, minSdk, targetSdk, module dependencies. A project can have multiple modules, each with its build.gradle. ## 3. What is applicationId in Android? **Answer** applicationId is the UNIQUE identifier of the app on Google Play Store and on device. Format: com.company.appname. Two apps with same applicationId cannot coexist. applicationId is defined in build.gradle: android { defaultConfig { applicationId 'com.example.app' } }. Don't confuse with code package name (can be different). ## 23 more questions available - What's the difference between versionCode and versionName? - What is minSdk in Android? Sign up for free: https://sharpskill.dev/en/login ## Other Android interview topics - [Android Fundamentals](https://sharpskill.dev/en/technologies/android/interview-questions/android-fundamentals.md): 24 questions, Junior - [Android UI and Resources](https://sharpskill.dev/en/technologies/android/interview-questions/android-ui-and-resources.md): 30 questions, Junior - [Android Lifecycle](https://sharpskill.dev/en/technologies/android/interview-questions/android-lifecycle.md): 30 questions, Junior - [Android Navigation](https://sharpskill.dev/en/technologies/android/interview-questions/android-navigation.md): 26 questions, Junior - [Android Data Management](https://sharpskill.dev/en/technologies/android/interview-questions/android-data-management.md): 29 questions, Junior - [Android Networking](https://sharpskill.dev/en/technologies/android/interview-questions/android-networking.md): 29 questions, Junior - [Android Testing](https://sharpskill.dev/en/technologies/android/interview-questions/android-testing.md): 28 questions, Junior - [Kotlin Language Essentials for Android](https://sharpskill.dev/en/technologies/android/interview-questions/android-kotlin-language-essentials.md): 24 questions, Junior - [Room Database](https://sharpskill.dev/en/technologies/android/interview-questions/android-room-database.md): 25 questions, Mid-Level - [Background Work](https://sharpskill.dev/en/technologies/android/interview-questions/android-background-work.md): 18 questions, Mid-Level - [Jetpack Compose](https://sharpskill.dev/en/technologies/android/interview-questions/android-compose.md): 28 questions, Mid-Level - [Permissions and Device Features](https://sharpskill.dev/en/technologies/android/interview-questions/android-permissions-and-device.md): 21 questions, Mid-Level - [Firebase for Android](https://sharpskill.dev/en/technologies/android/interview-questions/android-firebase.md): 23 questions, Mid-Level - [Android MVVM Architecture](https://sharpskill.dev/en/technologies/android/interview-questions/android-mvvm-architecture.md): 18 questions, Mid-Level - [Advanced Android Networking](https://sharpskill.dev/en/technologies/android/interview-questions/android-networking-advanced.md): 13 questions, Mid-Level - [Kotlin Collections and Operators](https://sharpskill.dev/en/technologies/android/interview-questions/android-kotlin-collections-operators.md): 20 questions, Mid-Level - [Kotlin Coroutines and Flow](https://sharpskill.dev/en/technologies/android/interview-questions/android-kotlin-coroutines-flow.md): 20 questions, Mid-Level - [Android Dependency Injection](https://sharpskill.dev/en/technologies/android/interview-questions/android-dependency-injection.md): 15 questions, Mid-Level - [Android MVI Architecture](https://sharpskill.dev/en/technologies/android/interview-questions/android-mvi-architecture.md): 17 questions, Mid-Level - [Android Clean Architecture](https://sharpskill.dev/en/technologies/android/interview-questions/android-clean-architecture.md): 21 questions, Senior - [Android Compose Advanced](https://sharpskill.dev/en/technologies/android/interview-questions/android-compose-advanced.md): 17 questions, Senior - [Android Performance and Monitoring](https://sharpskill.dev/en/technologies/android/interview-questions/android-performance-monitoring.md): 13 questions, Senior - [Android Security and Privacy](https://sharpskill.dev/en/technologies/android/interview-questions/android-security-privacy.md): 18 questions, Senior - [Android CI/CD and Release](https://sharpskill.dev/en/technologies/android/interview-questions/android-cicd-release.md): 15 questions, Senior - [Android UX and Form Factors](https://sharpskill.dev/en/technologies/android/interview-questions/android-ux-form-factors.md): 18 questions, Senior - [Android Testing Advanced](https://sharpskill.dev/en/technologies/android/interview-questions/android-testing-advanced.md): 18 questions, Senior --- Source: SharpSkill (https://sharpskill.dev), tech interview preparation for your real stack. 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