What is paging? What is virtual memory? What are the different ways you implement concepts of Virtual memory? What is MMU? What does it do? What are L1, L2 Caches? How do they differ from each other? Design of ARM processor What is a critical section? Why do we need process synchronization mechanisms? What are they? How are they implemented? What is the process? Differentiate process vs Threads? Why Thread is called a lightweight process? How many types of Semaphores are present? What are they? How do they differ?