Some people refer to only tracing algorithms (mark-sweep, copying, etc) as "garbage collection". The best reason I can think of is marketing. There are generat

Some people refer to only tracing algorithms (mark-sweep, copying, etc) as "garbage collection". The best reason I can think of is marketing. There are generational reference counting systems e.g. ulterior reference counting [1] and age-oriented collection [2]. "Tracing" usually refers to scanning a heap to work out liveness all at once, which reference counting doesn't do; though deferred reference counting scans the roots to collect, and ulterior reference counting traces a nursery. Deferring these (more common) updates to reference counts improves throughput considerably. [1] https://people.cs.umass.edu/~emery/classes/cmpsci691s-fall2004/papers/ulterior-reference-counting.pdf https://people.cs.umass.edu/~emery/classes/cmpsci691s-fall20... [2] https://users.cecs.anu.edu.au/~steveb/pubs/papers/aogc-cc-2005.pdf https://users.cecs.anu.edu.au/~steveb/pubs/papers/aogc-cc-20...