Java supports multithreading by allowing multiple threads to run concurrently, improving performance and resource utilization. Threads in Java can be created in two ways: by extending the Thread class or by implementing the Runnable interface. Extending Thread means inheriting from the Thread class, limiting further inheritance. Implementing Runnable promotes better object-oriented design and allows the class to extend other classes. Using Runnable is generally preferred in real-world applications. Both approaches override the run() method to define the thread’s task. To master Java concepts like this, consider joining a Java certification course.