Key Features in Java 21 LTS at a Glance

Java 21 LTS (Long-Term Support) was released in September 2023, replacing its predecessor, Java 17 LTS, after approximately two years. In between, there were biannual releases in the form of Java 18, 19, and 20. Logically, one should not expect a multitude of new features from these interim releases. However, overall, a lot has changed since Java 17 LTS. In this chapter, I would like to provide an overview of the new features introduced cumulatively with Java 21 LTS, in the form of so-called JEPs (JDK Enhancement Proposals). The following chapters introduce the significant enhancements from Java 18 to Java 21 LTS in detail.