Update garbage-collector.md

docs/core/runtime-config/garbage-collector.md

@@ -12,8 +12,8 @@ Settings are arranged into groups on this page. The settings within each group a
 
 > [!NOTE]
 >
-> - These settings can also be changed dynamically by the app as it's running, so any configuration options you set may be overridden.
-> - Some settings, such as [latency level](../../standard/garbage-collection/latency.md), are typically set only through the API at design time. Such settings are omitted from this page.
+> - These configurations are only read by the runtime when the GC is initialized (usually this means during the process startup time). If you change an environment variable when a process is already running, the change won't be reflected in that process. Settings that can be changed through APIs at run time, such as [latency level](../../standard/garbage-collection/latency.md), are omitted from this page.
+> - Because GC is per process, it rarely ever makes sense to set these configurations at the machine level. For example, you wouldn't want every .NET process on a machine to use server GC or the same heap hard limit.
 > - For number values, use decimal notation for settings in the *runtimeconfig.json* file and hexadecimal notation for environment variable settings. For hexadecimal values, you can specify them with or without the "0x" prefix.
 > - If you're using the environment variables, .NET 6 standardizes on the prefix `DOTNET_` instead of `COMPlus_`. However, the `COMPlus_` prefix will continue to work. If you're using a previous version of the .NET runtime, you should still use the `COMPlus_` prefix, for example, `COMPlus_gcServer`.