Java ConcurrentSkipListSet is a thread-safe, sorted set implementation that uses a skip list to store its elements. It supports concurrent access by multiple threads and ensures that all elements are kept in sorted order. Introduced in Java 2004 with Java 5, ConcurrentSkipListSet is part of Java's java.util.concurrent package and is used in applications where thread-safe, ordered sets are needed, such as in distributed systems or multi-threaded environments.

https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ConcurrentSkipListSet.html