This section gives a brief overview of RCU; more details are available elsewhere [McK98a,McK01b,McK02a]. Section 2.1 presents a visual example of RCU-based list manipulation, Section 2.2 contains a glossary of RCU-related terms, Section 2.3 presents concepts, Section 2.4 presents the RCU API, and Section 2.5 illustrates an analogy between RCU and reader-writer locking.