An APK (Android Package Kit) is the file format used to distribute and install applications on Android devices. It contains all the elements an app needs to install correctly, including code, resources, and manifest files. APKs can be downloaded from the Google Play Store or other sources. Users can also side load APKs manually, allowing access to apps not available in the store. Security checks are essential when installing APKs from unknown sources. https://modsapk.org