Gradle is a very flexible and powerful build system, but its concepts are relatively complex. As long as you grasp the core and keep the distinctions straight, it will not feel confusing.

Does the build script below look hard to understand?

buildscript {
    repository for build script dependencies
    repositories {
        mavenCentral()
    }
    // build script dependencies
    dependencies {
        classpath 'com.android.tools.build:gradle:4.2.0'
    }
}
repositories {
    mavenCentral()
    jcenter()
    google()
}
dependencies {
    implementation 'com.google.guava:guava:30.1-jre'
    testImplementation 'junit:junit:4.13.2'
}  
plugins {
      id 'com.android.application'
      id 'org.jetbrains.kotlin.jvm' version '1.5.10'
}

DevOps involves a great many tools, and every one of them comes with lengthy documentation; rote memorization will not get you anywhere. The right path is to understand the terminology of the core concepts, tell the different objects apart, and grasp what the designers had in mind, until you reach the point where it all feels “a matter of course” and “naturally so”.

There are three principal entities in Gradle: gradle itself, the project (the one to be built with gradle), and the build script (the one written with gradle).

Because Gradle is an extensible build system, its build scripts are executable scripts as well, rather than the xml markup language used by Ant and Maven; so both of them have dependencies.

Of course, the project has dependencies too.

gradle’s own dependencies are called plugins: they extend gradle’s own functionality, just as IDEA has plugins and Jenkins has plugins. They are declared with plugins.

The project’s dependencies do not directly provide functionality; rather, the code you write in the project needs to rely on these libraries. They are declared with dependencies.

The gradle build script is declared with buildscript — the name says it all.

Once these concepts are clear, take another look at the build script below with comments added, and it becomes very easy to understand!

// build script configuration  
buildscript {
    repository for build script dependencies
    repositories {
        mavenCentral()
    }
    // build script dependencies
    dependencies {
        classpath 'com.android.tools.build:gradle:4.2.0'
    }
}
// repository for project dependencies
repositories {
    mavenCentral()
    jcenter()
    google()
}
// project dependencies configuration
dependencies {
    implementation 'com.google.guava:guava:30.1-jre'
    testImplementation 'junit:junit:4.13.2'
}  
// plugins that the gradle build tool depends on
plugins {
      id 'com.android.application'
      id 'org.jetbrains.kotlin.jvm' version '1.5.10'
}