Garbage Collection (GC) is one of two memory and object lifetime management models used by the Elements compiler, next to Automatic Reference Counting (ARC). It is used on the .NET and Java platforms.
Garbage Collection manages object life cycles by having the managed infrastructure provided by the Common Language Runtime (on .NET and Mono) and Java Runtime Environment (on Java) keep track of when objects are no longer referenced by any part of your code, so that the underlying memory and resources can automatically be freed when they are no longer needed.
In essence, GC (as well as ARC) alleviates the developer of the burden of manually keeping track of object ownership, eliminating explicit calls to "free" or "destroy" methods or so-called destructors.
Only objects that represent so-called "unmanaged resources", such as file handles, network sockets or the like, might need special consideration to be deterministically disposed of — which can be accomplished using the Dispose Pattern.
.NET and Java Only
GC is used on .NET and Java only. The Cocoa platform uses Automatic Reference Counting.
Comparing GC and ARC
You can find a more detailed comparison of GC and ARC and how the differences affect the Oxygene code you write in the Automatic Reference Counting vs. Garbage Collection topic.