Glossary: APK, XAPK, OBB and MOD Explained

New to downloading Android apps outside the Play Store? This glossary explains the terms you will run into on APKGStore and across the Android world, in plain language. Bookmark it and refer back whenever a word is unfamiliar.

APK

APK stands for Android Package Kit. It is the standard file format Android uses to distribute and install apps — the same kind of package Google Play delivers behind the scenes. When you download an app from outside the Play Store, you install it from an .apk file. See our install guide to learn how.

XAPK

An XAPK is a bundle that packs an APK together with its extra data (OBB) files in a single .xapk archive. Larger games use this format because they need additional resources. You cannot install an XAPK directly — you open it with a free XAPK installer app, which unpacks the APK and the data and installs them together.

OBB

An OBB file is an “opaque binary blob” — a data file that holds a game’s extra content such as high-resolution textures, audio and assets, kept separately from the APK. Big games ship an APK plus an OBB. You install the APK first, then place the OBB in the Android/obb/<package.name>/ folder so the game can find it.

MOD APK

A MOD is a modified version of an app or game, altered by the community to unlock premium features, remove ads, or change gameplay (for example, unlimited coins or unlocked levels). On APKGStore, MODs are clearly labelled and described, and are provided for testing and educational purposes only.

Sideloading

Sideloading simply means installing an app from an APK file rather than from an official app store. It is a normal, built-in Android capability — you just need to allow installs from your browser or file manager the first time.

Unknown sources

“Unknown sources” (on newer Android, “Install unknown apps”) is the permission that lets a specific app — like your browser or file manager — install APKs. You grant it per app in Settings, and you can turn it off again afterwards for extra safety.

Google Play Protect

Play Protect is Google’s built-in security scanner on Android. It checks apps for harmful behaviour, including ones installed from APKs. We recommend leaving it on — it works alongside the verification we already do on every file.

Package name

The package name is an app’s unique identifier, written in reverse-domain style (for example, com.example.app). Android uses it to tell apps apart, and it is the folder name you use when placing OBB data for a game.

Signature / signed APK

Every legitimate APK is digitally signed by its developer. The signature proves the file came from that developer and has not been tampered with. We check signatures as part of verifying each file, which is how you can trust that the app you download is the genuine one.

Version code & version name

The version name is the friendly version you see (such as 2.5.1), while the version code is an internal number Android uses to know which build is newer. When we update an app page, both reflect the latest release so you always get the current version.

Minimum Android version

This is the oldest Android release an app will run on. If your phone’s Android version is lower than an app’s minimum, it will not install — each app page lists this requirement so you can check before downloading.