Pro C# 2010 and the .NET 4 Platform, Fifth Edition

8.4. Understanding Object Generations

When the CLR is attempting to locate unreachable objects, is does not literally examine each and every object placed on the managed heap. Doing so, obviously, would involve considerable time, especially in larger (i.e., real-world) applications.

To help optimize the process, each object on the heap is assigned to a specific "generation." The idea behind generations is simple: the longer an object has existed on the heap, the more likely it is to stay there. For example, the class that defined the main window of a desktop application will be in memory until the program terminates. Conversely, objects that have only recently been placed on the heap (such as an object allocated within a method scope) are likely ...