Questions

1. What is the difference between application and system programming?
2. What is an API? Why are APIs so important?
3. Could you explain how protection rings work?
4. Can you make some examples of what cannot be done in user space?
5. What's a system call?
6. Which calls are used in Unix to manage a process?
7. Why is POSIX useful?
8. Is Windows POSIX compliant?