APK Full Form is Andriod Package Kit. ( .apk ) is File Extension. APK is the file format used to distribute and install application software and middleware onto Google’s Android operating system; very similar to an MSI package in Windows or a Deb package in Debian-based operating systems like Ubuntu.
To make an APK file, a program for Android is first compiled, and then all of its parts are packaged into one file. An APK file contains all of that program’s code (such as .dex files), resources, assets, certificates, and manifest file. As is the case with many file formats, APK files can have any name needed, provided that the file name ends in “.apk”