What is Swap Space, I/O and CPU Bound Jobs?

Hi my name is B.Lie
I am facing few problem in that question I tried my best but not get its answer that's why I m requesting to all my friends to tell me the solution of this question.
Tell me that What is SWAP SPACE?
And also tell me that Why the long-term scheduler must select a good mix of I/O bound and CPU BOUND JOBS?
