“Bundle version” 和 “Bundle versions string, short”的区别

Bundle version is the internal version number of your app. 

Short version string is the publically visible version of your app. 

So for example, if you iterate your version number every time you do an internal build for your beta testers (or whatever), your bundle version might be 2.0.0.12345b7, but you don't want the public to see that, so you set your short version string to 2.0. 

Short version string seems to be optional, so if you leave it blank then the bundle version is what people will see (i.e. that's what will be displayed on the App Store). 

Your short version string can't have more than 3 parts, e.g. 2.0.1 is okay, but 2.0.0.1 isn't. If you don't have a short version string, then the same rules apply to your bundle ID (basically the public app version has this restriction and the private app version doesn't).