When updating a mobile app, say, from Google Play, how can it apply the same update to two people who both may have different versions prior to updating?

Question

When updating a mobile app, say, from Google Play, how can it apply the same update to two people who both may have different versions prior to updating?

In: Technology

Answer 1

Most of the time the update contain a completer replacement for the program. So the download it the same as if you just install it for the first time. Configuration files are kept so you setting in the app is still there after you update it.

On larger program like operation system you can have updates that is differential so you only changes stuff that is changed but that increase complexity and for a mobile app that is just a few megabytes it is not worth it.