Technology of Package Split?

Split the package (APK or IPA) of a game from a big one such as 500MB into a small one such as less than 100MB. Players only need to install the small package and rest resources will be loaded at background while playing, which significantly improves the distributing efficiency.

Download while Playing:

The package is split into a small one, which can be played by end users immediately after installed, and rest resources are downloaded in background while playing, which makes no difference between the whole package and the small package.
Download before Playing:

A game package can be split into any size game developers want, such as less than 100MB to cover the non-WiFi users. This package cannot be played immediately after installed and need to download some game resources to reach the resource limit of Download while Playing.