Reference counting and tracing are the two main approaches for garbage collection. See, for example, https://courses.cs.washington.edu/courses/cse590p/05au/p50-

Reference counting and tracing are the two main approaches for garbage collection. See, for example, https://courses.cs.washington.edu/courses/cse590p/05au/p50-bacon.pdf https://courses.cs.washington.edu/courses/cse590p/05au/p50-b... While tracing is considered to have better throughput and reference counting to have a lower footprint, as the liked paper shows, they are really on a spectrum of techniques with different tradeoffs.