This is sometimes referred to as a multi-module project.
Gradle refers to modules as subprojects.

A multi-project build consists of one root project and one or more subprojects.

[[sec:project_structure]]
== Multi-Project structure

The following represents the structure of a multi-project build that contains two subprojects:

image::multi-project-structure.png[]

The directory structure should look as follows:

        }
    }

    def "reports cross project access from model builder while fetching custom tooling model"() {
        given:
        settingsFile << """
            include('a')
            include('b')
        """
        withSomeToolingModelBuilderPluginInBuildSrc("""
            project.subprojects.each { it.extensions }
        """)

// tag::include-subprojects[]
include("app")
include("data-model")
//include("database-logic")
// end::include-subprojects[]

}

/** Configure building for Java+Kotlin projects. */
subprojects {
  val project = this@subprojects
  if (project.name == "okhttp-bom") return@subprojects

  if (project.name == "okhttp-android") return@subprojects
  if (project.name == "android-test") return@subprojects
  if (project.name == "regression-test") return@subprojects
  if (project.name == "android-test-app") return@subprojects
  if (project.name == "container-tests") return@subprojects

// tag::include-subprojects[]
include("app")
include("data-model")
//include("database-logic")
// end::include-subprojects[]

        private Map<String, String> subprojects

        @Override
        TestFile getBuildDir(String projectPath, TestFile projectRoot) {
            if (projectPath == ':') {
                return projectRoot.file("build")
            } else {
                if (subprojects == null) {
                    ArrayNode arr = (ArrayNode) projectRoot.file(".teamcity/subprojects.json").withInputStream {

pluginManagement {
  repositories {
      maven {
        url './maven-repo'
      }
  }
}

// tag::include-subprojects[]
include 'hello-a'
include 'hello-b'
include 'goodbye-c'
// end::include-subprojects[]

This sample shows how to aggregate code coverage across multiple Java subprojects using link:https://www.jacoco.org/jacoco/[JaCoCo].  The link:{userManualPath}/jacoco_report_aggregation_plugin.html[jacoco-report-aggregation plugin] provides this ability via a standalone project used to specify _which_ subprojects to include for aggregation.

This sample shows how to aggregate test results across multiple Java subprojects.  The link:{userManualPath}/test_report_aggregation_plugin.html[test-report-aggregation plugin] provides this ability via a standalone project used to specify _which_ subprojects to include for aggregation.

        given:
        createDirs("subprojectA", "subprojectB", "subprojectC", "subprojectD")
        settingsFile << """
rootProject.name = "root"
include 'subprojectA'
include 'subprojectB'
include 'subprojectC'
include 'subprojectD'
"""

        buildFile << """
configure(project(':subprojectA')) {
    apply plugin: 'java'
    apply plugin: 'idea'