Let's start with a non-generational (non-generation-based) GC approach.

Non-generational GC is a garbage collector that does not divide the heap into generations (young, old, etc.). Instead, it considers the entire heap at once during each collection. This approach is simpler to implement but usually less efficient in terms of performance, as it does not account for differences in object lifetimes.

An example could be a simple mark-and-sweep algorithm, where all reachable objects are first marked, and then unmarked objects are removed. Such a GC is often used in small systems or where high garbage collection performance is not required.

Main features:

• No division into generations.
• Full heap check during each collection.
• Longer pause times during collection.
• Simpler to implement.

In Java, this approach is rarely used in modern JVMs, as generational GC is significantly more efficient for most applications.