What is the difference between AAB and APK file for Android?

An AAB or Android App Bundle is a publishing format for Android apps that contains all of your app’s compiled code and resources while deferring APK generation and Google Play signing.

The distinction between APK and AAB files is found in resources. Everything except programming code, such as images, language files, and audio, is the resource in an application. While installing an app from the Play Store, Google will deploy an APK customized from AAB with the required resources.

An APK or Android Application Package is made up of app codes, resources like audio, images, video, etc., and a developer-generated app signing key. In an ideal situation, according to the user’s location, screen density, and processor type, developers have to create and upload multiple APKs to the Play Store to make the app compatible with every device. Most developers create a Universal APK that includes all of the resources (language packs, codes, and more) even if you don’t need most of them on that specific device to avoid creating multiple APKs. This results in a bulky APK with a larger app size, which takes longer to install and consumes more bandwidth.

APK is the Android packaging format that users can install directly on their devices, whereas AAB is a publishing format that developers provide to Google. With the introduction of AAB, developers no longer have to worry about developing multiple APKs for different devices. Developers submit the AAB file including compiled codes, resources, language packs, and the private app signing key to Google. Google can now generate and offer optimized APKs to consumers based on the configuration of their device. It will help both developers and users because the size of AAB files will be lowered, and consumers will be able to download apps that are less in size, which will install faster and consume less data on low-end devices.

The key benefits of an AAB file are that it reduces the size of the software and allows developers to customize it.