Why do apps update?

[jamesyboy1111]

Hello, so this may sound like a stupid question but it's something I couldn't figure out. Whats the difference between the app updating and not updating? Take Snapchat for example. Sometimes you get an update for things like bug fixes but also they don't need to update when they want to implement something such as a new filter. If someone could explain when it's required to update something and it's not that would be awesome! Sorry for sounding like a complete retard I just couldn't figure it out.
Thanks in advance!

 

[modernwar99]

I think ios and android apps can update themselves through the app unless the update required that the core app needs to be modified, which would require it to be rebuilt, resigned, and reuploaded as an update through iTunes or Google Play. Like adding a filter in snapchat, snapchat most likely just downloads the updated file containing the filter effects from their servers and replaces the old one. While bug fixes require tweaking the app's code and updating the core app requires a update through iTunes/Google Play.

 

[JQB45]

If any of the executable code changes for instance during a bug fix or a brand new feature then an update is required.
Something like a filter they could have planned for with the initial build and so it may just be a configuration change not requiring an update.

 

[kanewolf]

An update is required if the code running on your device is to be changed. It could be a bug fix, or a feature update. The developer has released new code to the app store. The OS update mechanisms then detect it and update.