Sealed classes are a powerful feature added to Java 17 that allows modeling our business domain data types in a very concise way and together with other features allows us to build more secure and robust software.
Annotation interfaces in Java are a specialized kind of interface declared with a distinct syntax, intended to augment our code with more capabilities, mainly by means of reflection.
Interfaces in Java define behaviors, which are expressed as a group of methods in their bodies. They establish a well-defined API contract between two parties and promote loose coupling.