What is Ruby’s object lifetime model from allocation to garbage collection?

Objects go from allocation → young generation → promotion → old generation → GC sweep.

Ruby allocates objects in young generation heap slots. If they survive GC cycles, they are promoted to old generation. GC periodically marks reachable objects from root set (stack, globals, constants). Unmarked objects are swept and memory reused. This lifecycle optimizes for short-lived objects common in web apps.