Answer & Explanation
Reserved words are words that cannot be used as object or variable names in a Java program because they're already used by the syntax of the Java programming language.
Java reserved words are keywords that are reserved by Java functions or other uses that cannot be used as identifiers (e.g., variable names, function names, class names).
If a reserved word was used as a variable you would get an error or unexpected result.
Examples : Int, Long, Abstract, Class, Break, Catch, Case, Public, Static, Void,...