The .NET Generator Standard Classes in an executable format (.dll or .exe) are downloaded from the internet and installed automatically when building any Object. In this way, a package manager mechanism is used to download the binaries via NuGet.
The NuGet package manager does not necessarily access the internet every time you run a Build. The reason is that NuGet has a cache (located by default in <user>\.nuget\package), where packages are downloaded. If the cache is cleared (*), the packages are downloaded again when you do the Build.
Moving Standard Classes to a package manager in the cloud provides convenience and speed when you need to get a HotFix from GeneXus or third parties (for example, Log4Net update). More information at Standard classes specific version property.
In addition, it is possible to configure the HotFix to update automatically every time one is available and you build the KB or keep a fixed version. More information at Standard classes update policy property.
The compatibility of the generated code is guaranteed. However, you should consider the offline scenario.
Since GeneXus 17 Upgrade 11.
GeneXus Standard Classes
.NET Generator Standard Classes - FAQ