What are the main differences between Java 11 and Java 17 releases?

The main differences between Java 11 and Java 17 are related to new features, performance improvements, and support for new language constructs.

Java 11 is a long-term support (LTS) release released in 2018, which introduced:

• Built-in support for the HTTP Client API for easier HTTP communication.
• Improvements in working with local variables (var).
• Removal of deprecated modules and APIs.
• Support for Unicode 10.

Java 17 is also an LTS release, released in 2021, and includes:

• New language constructs, such as pattern matching for instanceof operators.
• Stabilization of sealed classes (inheritance restrictions).
• Improvements in working with text blocks for easier multi-line text.
• Performance and security enhancements in JVM.
• Support for newer Unicode versions.

Thus, Java 17 expands the language and platform capabilities, making code more expressive and efficient, while maintaining backward compatibility with Java 11.