The "static" keyword in Java is used to declare variables, methods, and nested classes that belong to the class itself, rather than instances of the class. It allows accessing them without creating an object of the class. 30. What is the difference between "==" and ".equals()" in Java? The "==" operator in Java is used to compare the equality of object references, while the ".equals()" method is used to compare the equality of object values. The ".equals()" method can be overridden to provide custom equality comparison. 31. What is the purpose of the "super" keyword in Java? The "super" keyword in Java is used to refer to the superclass of a class. It can be used to access superclass members, invoke superclass constructors, or differentiate between superclass and subclass members with the same name. 32. What is a thread in Java? A thread in Java is a lightweight unit of execution within a program. It allows concurrent execution of multiple tasks or activities, enabling better utilization of system resources. 33. How do you create and start a thread in Java? To create and start a thread in Java, you can either extend the "Thread" class and override the "run()" method, or implement the "Runnable" interface and pass it to a new "Thread" object. Then call the "start()" method on the thread object to begin execution. 34. What is synchronization in Java? Synchronization in Java is a technique used to control the access and execution of multiple threads to ensure that only one thread can access a shared resource or code block at a time. 35. What is the difference between the "synchronized" block and the "synchronized" method?