Android studio: new project vs new module

Question

Android Studio uses the concept of modules, whereas other IDEs like Eclipse use projects. However AS File menu has the option to create a New Module as well as a new Project.

What are the differences between these two if any?

Which one is recommended to use?

score 176 · Answer 1 · answered Aug 20 '13 at 08:03

176

KISS answer:

module in Android Studio is like a project in Eclipse

project in Android Studio is like a workspace in Eclipse

answered Aug 20 '13 at 08:03

Oded Breiner

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I have been struggling with this issue myself and while this seems to be the conceptual case, I am confused. When I create a new 'Project' in Android Studio I am presented with a wizard that asks me about things like Theme, use of ActionBar, Grid Layout and such. I would have thought these things would be left to the Module. If these questions are just so the appropriate support libs are added to the 'Project' then I understand, but I also see these same things when creating a new module. Quite confusing. – Scott Naef Jan 01 '14 at 22:59
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You have a point, but the accepted answer just notes the problems with trying to work with android studio as if it was eclipse. Most people looking for this question just need to know what is the analogy. – Oded Breiner Apr 18 '14 at 10:41
Creating a new project in Android does not looks more like an app with manifest / res / and src - as apposed to a "workspace". When creating a Module, two o the types offered are 1) application module and 2) android library module. #1 seems redundant to "new project" and #1 and #2 seem the same. – user1679130 May 07 '15 at 19:59
oO is a module really that much?! – Martin Pfeffer Oct 30 '15 at 03:41
1

@MartinPfeffer - no, but that's the closest analogy, read more here: http://www.jetbrains.org/intellij/sdk/docs/basics/project_structure.html – Oded Breiner Oct 30 '15 at 11:47
after updating AS and gradle to latest, I get the "no module" message when trying to run the project, and in the "android" view (as opposed to e.g. project view), this project does no longer contain an arrow that can be tilted down, i.e. AS do not see this module anymore. Where is the module defined? Any tips how to correct the error? – carl Feb 17 '19 at 20:32

Dalmas · Accepted Answer · 2013-09-17T11:13:49.453

105

From the documentation (Android Studio is based on Intellij IDEA) :

Whatever you do in IntelliJ IDEA, you do that in the context of a project. A project is an organizational unit that represents a complete software solution.

Your finished product may be decomposed into a series of discrete, isolated modules, but it's a project definition that brings them together and ties them into a greater whole.

For Android, it means one project per app, and one module per library and per test app.

There are multiple issues if you try to build multiple apps within the same project. It's possible, but if you try (like I did), you will see that almost everything is designed to work with a single app per project.

For example, there is an option to "rebuild the project", which makes no sense with multiple apps, many other project settings would be useless, and the built-in VCS system isn't great when you have multiple repositories.

edited Sep 17 '13 at 11:13

answered Jun 19 '13 at 09:37

Dalmas

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"It means one project per app, and one module per library and per test app"... What does this mean? If a "test app" is an app, then there can only be two modules per project, one for an app (regular or test app) and one for a library. – LarsH Jun 24 '15 at 14:50
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@LarsH, I would rephrase it as: "a project per main app" – Nico Jul 31 '15 at 11:11
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this is not the answer. bad answer – metis Jun 04 '18 at 15:13

score 40 · Answer 3 · edited Jun 20 '20 at 09:12

40

A project in Android Studio represents a complete Android app. Android Studio projects consist of one or more modules.

A module is a component of your app that you can build, test, or debug independently.

Modules contain the source code and resources for your app.

edited Jun 20 '20 at 09:12

Community

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answered May 14 '14 at 15:15

TooCool

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Manish Kumar Sharma · Answer 4 · 2019-10-16T05:40:17.653

From updated docs [2019]:

Modules provide a container for your app's source code, resource files, and app level settings, such as the module-level build file and Android manifest file. Each module can be independently built, tested, and debugged.

Android Studio uses modules to make it easy to add new devices to your project. By following a few simple steps in Android Studio, you can create a module to contain code that's specific to a device type, such as Wear OS or Android TV. Android Studio automatically creates module directories, such as source and resource directories, and a default build.gradle file appropriate for the device type. Also, Android Studio creates device modules with recommended build configurations, such as using the Leanback library for Android TV modules.

Ex:

Phone & Tablet Module
Android Wear Module
Android TV Module
Glass Module

Besides these, you can also have a "local library module". Say, you develop a Account Management Framework as a library module to be used ultimately in your App, you can do it as a separate module in the same project. To include that in your App, you would have to write something like,

compile project(':mylibrary')

Docs say,

This declares a dependency on an Android library module named "mylibrary" (this name must match the library name defined as an include in your settings.gradle file). It requires the build system to compile the library module with your app module and include the resulting AAR file in your APK.

Lastly, Intellij mentions some more details about Module configuration files:

Configuration information for a module is stored in a .iml module file. By default, such a file is located in the module's content root folder.

Development teams, normally, share the .iml module files through version control.

This .iml file is a bit scary to look at. Here is an example from my project:

<?xml version="1.0" encoding="UTF-8"?>
<module external.linked.project.id=":app" external.linked.project.path="$MODULE_DIR$" external.root.project.path="$MODULE_DIR$/.." external.system.id="GRADLE" external.system.module.group="LearnCity" external.system.module.version="unspecified" type="JAVA_MODULE" version="4">
  <component name="FacetManager">
    <facet type="android-gradle" name="Android-Gradle">
      <configuration>
        <option name="GRADLE_PROJECT_PATH" value=":app" />
      </configuration>
    </facet>
    <facet type="android" name="Android">
      <configuration>
        <option name="SELECTED_BUILD_VARIANT" value="debug" />
        <option name="ASSEMBLE_TASK_NAME" value="assembleDebug" />
        <option name="COMPILE_JAVA_TASK_NAME" value="compileDebugSources" />
        <afterSyncTasks>
          <task>generateDebugSources</task>
        </afterSyncTasks>
        <option name="ALLOW_USER_CONFIGURATION" value="false" />
        <option name="MANIFEST_FILE_RELATIVE_PATH" value="/src/main/AndroidManifest.xml" />
        <option name="RES_FOLDER_RELATIVE_PATH" value="/src/main/res/layouts/common/layout/ver3/layout" />
        <option name="RES_FOLDERS_RELATIVE_PATH" value="file://$MODULE_DIR$/src/main/res/layouts/common/layout/ver3/layout;file://$MODULE_DIR$/src/main/res/layouts/common/layout/ver3;file://$MODULE_DIR$/src/main/res/layouts/common/layout/ver2/layout;file://$MODULE_DIR$/src/main/res/layouts/common/layout/ver2;file://$MODULE_DIR$/src/main/res/layouts/common/layout/ver1/layout;file://$MODULE_DIR$/src/main/res/layouts/common/layout/ver1;file://$MODULE_DIR$/src/main/res/layouts/common/layout/ver0/layout;file://$MODULE_DIR$/src/main/res/layouts/common/layout/ver0;file://$MODULE_DIR$/src/main/res/layouts/common/layout;file://$MODULE_DIR$/src/main/res/layouts/learner/layout;file://$MODULE_DIR$/src/main/res/layouts/tutor/layout;file://$MODULE_DIR$/src/main/res/layouts/obsolete/layout;file://$MODULE_DIR$/src/main/res/layouts/common;file://$MODULE_DIR$/src/main/res/layouts/learner;file://$MODULE_DIR$/src/main/res/layouts/tutor;file://$MODULE_DIR$/src/main/res/layouts/obsolete;file://$MODULE_DIR$/src/main/res/layouts;file://$MODULE_DIR$/src/main/res;file://$MODULE_DIR$/src/debug/res" />
        <option name="ASSETS_FOLDER_RELATIVE_PATH" value="/src/main/assets" />
      </configuration>
    </facet>
  </component>
  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_7" inherit-compiler-output="false">
    <output url="file://$MODULE_DIR$/build/intermediates/classes/debug" />
    <output-test url="file://$MODULE_DIR$/build/intermediates/classes/test/debug" />
    <exclude-output />
    <content url="file://$MODULE_DIR$">
      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/r/debug" isTestSource="false" generated="true" />
      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/aidl/debug" isTestSource="false" generated="true" />
      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/buildConfig/debug" isTestSource="false" generated="true" />
      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/rs/debug" isTestSource="false" generated="true" />
      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/apt/debug" isTestSource="false" generated="true" />
      <sourceFolder url="file://$MODULE_DIR$/build/generated/res/google-services/debug" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/build/generated/res/rs/debug" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/build/generated/res/resValues/debug" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/r/androidTest/debug" isTestSource="true" generated="true" />
      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/aidl/androidTest/debug" isTestSource="true" generated="true" />
      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/buildConfig/androidTest/debug" isTestSource="true" generated="true" />
      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/rs/androidTest/debug" isTestSource="true" generated="true" />
      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/apt/androidTest/debug" isTestSource="true" generated="true" />
      <sourceFolder url="file://$MODULE_DIR$/build/generated/res/rs/androidTest/debug" type="java-test-resource" />
      <sourceFolder url="file://$MODULE_DIR$/build/generated/res/resValues/androidTest/debug" type="java-test-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/debug/res" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/debug/resources" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/debug/assets" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/debug/aidl" isTestSource="false" />
      <sourceFolder url="file://$MODULE_DIR$/src/debug/java" isTestSource="false" />
      <sourceFolder url="file://$MODULE_DIR$/src/debug/rs" isTestSource="false" />
      <sourceFolder url="file://$MODULE_DIR$/src/debug/shaders" isTestSource="false" />
      <sourceFolder url="file://$MODULE_DIR$/src/testDebug/res" type="java-test-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/testDebug/resources" type="java-test-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/testDebug/assets" type="java-test-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/testDebug/aidl" isTestSource="true" />
      <sourceFolder url="file://$MODULE_DIR$/src/testDebug/java" isTestSource="true" />
      <sourceFolder url="file://$MODULE_DIR$/src/testDebug/rs" isTestSource="true" />
      <sourceFolder url="file://$MODULE_DIR$/src/testDebug/shaders" isTestSource="true" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/res/layouts/common/layout/ver3/layout" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/res/layouts/common/layout/ver3" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/res/layouts/common/layout/ver2/layout" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/res/layouts/common/layout/ver2" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/res/layouts/common/layout/ver1/layout" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/res/layouts/common/layout/ver1" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/res/layouts/common/layout/ver0/layout" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/res/layouts/common/layout/ver0" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/res/layouts/common/layout" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/res/layouts/learner/layout" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/res/layouts/tutor/layout" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/res/layouts/obsolete/layout" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/res/layouts/common" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/res/layouts/learner" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/res/layouts/tutor" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/res/layouts/obsolete" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/res/layouts" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/res" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/resources" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/assets" type="java-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/aidl" isTestSource="false" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/java" isTestSource="false" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/rs" isTestSource="false" />
      <sourceFolder url="file://$MODULE_DIR$/src/main/shaders" isTestSource="false" />
      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/res" type="java-test-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/resources" type="java-test-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/assets" type="java-test-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/aidl" isTestSource="true" />
      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/java" isTestSource="true" />
      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/rs" isTestSource="true" />
      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/shaders" isTestSource="true" />
      <sourceFolder url="file://$MODULE_DIR$/src/test/res" type="java-test-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/test/resources" type="java-test-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/test/assets" type="java-test-resource" />
      <sourceFolder url="file://$MODULE_DIR$/src/test/aidl" isTestSource="true" />
      <sourceFolder url="file://$MODULE_DIR$/src/test/java" isTestSource="true" />
      <sourceFolder url="file://$MODULE_DIR$/src/test/rs" isTestSource="true" />
      <sourceFolder url="file://$MODULE_DIR$/src/test/shaders" isTestSource="true" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/assets" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/blame" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/builds" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/classes" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/incremental" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/incremental-classes" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/incremental-runtime-classes" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/incremental-safeguard" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/incremental-verifier" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/instant-run-resources" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/instant-run-support" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/jniLibs" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/manifests" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/multi-dex" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/pre-dexed" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/reload-dex" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/res" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/restart-dex" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/rs" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/shaders" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/split-apk" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/symbols" />
      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/transforms" />
      <excludeFolder url="file://$MODULE_DIR$/build/outputs" />
      <excludeFolder url="file://$MODULE_DIR$/build/tmp" />
    </content>
    <orderEntry type="jdk" jdkName="Android API 25 Platform" jdkType="Android SDK" />
    <orderEntry type="sourceFolder" forTests="false" />
    <orderEntry type="library" exported="" name="google-http-client-android-1.22.0" level="project" />
    <orderEntry type="library" exported="" name="firebase-analytics-10.2.0" level="project" />
    <orderEntry type="library" exported="" name="firebase-core-10.2.0" level="project" />
    <orderEntry type="library" exported="" name="play-services-auth-base-10.2.0" level="project" />
    <orderEntry type="library" exported="" name="gson-2.8.0" level="project" />
    <orderEntry type="library" exported="" name="play-services-tasks-10.2.0" level="project" />
    <orderEntry type="library" exported="" name="constraint-layout-1.0.2" level="project" />
    <orderEntry type="library" exported="" name="appengine-api-1.0-sdk-1.9.50" level="project" />
    <orderEntry type="library" exported="" name="design-25.3.0" level="project" />
    <orderEntry type="library" exported="" name="android-job-1.1.8" level="project" />
    <orderEntry type="library" exported="" name="transition-25.3.0" level="project" />
    <orderEntry type="library" exported="" name="play-services-base-10.2.0" level="project" />
    <orderEntry type="library" exported="" name="multispinner-0.1.1" level="project" />
    <orderEntry type="library" exported="" name="play-services-auth-10.2.0" level="project" />
    <orderEntry type="library" exported="" name="support-core-ui-25.3.0" level="project" />
    <orderEntry type="library" exported="" name="simpleratingbar-0.1.5" level="project" />
    <orderEntry type="library" exported="" name="play-services-maps-10.2.0" level="project" />
    <orderEntry type="library" exported="" name="play-services-location-10.2.0" level="project" />
    <orderEntry type="library" exported="" name="firebase-iid-10.2.0" level="project" />
    <orderEntry type="library" exported="" name="support-core-utils-25.3.0" level="project" />
    <orderEntry type="library" exported="" name="jsr305-2.0.1" level="project" />
    <orderEntry type="library" exported="" name="support-fragment-25.3.0" level="project" />
    <orderEntry type="library" exported="" scope="TEST" name="multidex-instrumentation-1.0.1" level="project" />
    <orderEntry type="library" exported="" name="constraint-layout-solver-1.0.2" level="project" />
    <orderEntry type="library" exported="" name="androidannotations-api-3.2" level="project" />
    <orderEntry type="library" exported="" name="java-uuid-generator-3.1.4" level="project" />
    <orderEntry type="library" exported="" name="google-http-client-1.22.0" level="project" />
    <orderEntry type="library" exported="" name="firebase-messaging-10.2.0" level="project" />
    <orderEntry type="library" exported="" name="firebase-analytics-impl-10.2.0" level="project" />
    <orderEntry type="library" exported="" name="firebase-common-10.2.0" level="project" />
    <orderEntry type="library" exported="" name="eventbus-3.0.0" level="project" />
    <orderEntry type="library" exported="" name="cat-1.0.5" level="project" />
    <orderEntry type="library" exported="" name="play-services-basement-10.2.0" level="project" />
    <orderEntry type="library" exported="" name="support-compat-25.3.0" level="project" />
    <orderEntry type="library" exported="" name="support-v4-25.3.0" level="project" />
    <orderEntry type="library" exported="" name="multidex-1.0.1" level="project" />
    <orderEntry type="library" exported="" scope="TEST" name="hamcrest-core-1.3" level="project" />
    <orderEntry type="library" exported="" name="support-media-compat-25.3.0" level="project" />
    <orderEntry type="library" exported="" scope="TEST" name="junit-4.12" level="project" />
    <orderEntry type="library" exported="" name="recyclerview-v7-25.3.0" level="project" />
    <orderEntry type="library" exported="" name="appcompat-v7-25.3.0" level="project" />
    <orderEntry type="library" exported="" name="animated-vector-drawable-25.3.0" level="project" />
    <orderEntry type="library" exported="" name="support-annotations-25.3.0" level="project" />
    <orderEntry type="library" exported="" name="support-vector-drawable-25.3.0" level="project" />
    <orderEntry type="module" module-name="backend" exported="" />
    <orderEntry type="library" exported="" name="android-android-25" level="project" />
  </component>
</module>

While the accepted answer was dead-on, time and Google's tendency to change like the wind has rendered it obsolete (dare I say, `@Deprecated`?). This makes much more sense. — SMBiggs, Feb 01 '19 at 06:10

score 1 · Answer 5 · answered Mar 27 '14 at 11:46

IntelliJ IDEA creates a project for the entire code base you work with, and a module for each of its individual components. So, IntelliJ IDEA module is more like an Eclipse project, and project is roughly similar to Eclipse workspace. There's no exact equivalent to Eclipse's workspace that contains all your work, but you can open multiple projects in multiple frames at the same time.

Here is the IntelliJ IDEA Q&A for Eclipse Users page-

http://www.jetbrains.com/idea/documentation/migration_faq.html

score 1 · Answer 6 · answered Mar 30 '15 at 15:14

1

Modules are like apkLibs ie it has its own res, manifest, tests etc but the main app usually uses various apklibs/modules to help put it all together in one solution

answered Mar 30 '15 at 15:14

Jono

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score 0 · Answer 7 · answered May 30 '21 at 16:28

Android Studio structure

Project <- Module <- Configuration

Project consolidates single or multiple modules, were module can have none, one or multiple configurations(Application, Test...)

Module is used to group, reuse, build time purpose. It can be created for application or for library/framework

Single Project allows you to manage all cases which you can run into in scope of the same business project. For example you are developing some SDK, that is why you should have SDK module, also you should provide consumers by Demo Application(each for Java and Kotlin languages), that is why you create application module which includes your SDK, then you decide to modularise your SDK and create separate modules with dependencies between them.

[Xcode structure]
[Swift module]

score -5 · Answer 8 · answered Jul 27 '14 at 06:15

-5

Referring to @Oded Breiner answer I would say that:

module in Android Studio is like a project in Eclipse

project in Android Studio is like a working set in Eclipse

answered Jul 27 '14 at 06:15

Federico Iosue

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Not really. IMHO "working sets" in Eclipse are just "filters" for the current workspace. You can't have two workspaces in Eclipse, as well as you can't have two projects opened in the same instance of Android Studio (in fact when you open another project, you have to replace the former, or to open the latter in a new window) – ocramot Apr 30 '15 at 12:13
1

You could suggest edit instead referring original answer with little changes! – Ayub Apr 24 '16 at 11:50

Android studio: new project vs new module

8 Answers8

From updated docs [2019]:

Modules provide a container for your app's source code, resource files, and app level settings, such as the module-level build file and Android manifest file. Each module can be independently built, tested, and debugged.

Linked