Computer Science Homework Help

I’m working on a Cyber Security question and need guidance to help me study.

1) What is the difference between vision and mission?
2) What is meant by project strategy?
3) Why is time management critical?
4) What does research suggest as a best practice for how much time should be spent in initiating and planning activities for projects?
    Do you think that estimate is realistic? Why or why not?
    How does spending more time on planning help reduce time spent on executing?