How to over clock RAM in windows 8.1

Is it safe to over clock RAM? What applications are used for over clocking the RAM? What is the difference between over clocking RAM and over clocking CPU? Are both the same? Which clocking makes computer hotter? Why does one support over clocking if it dangerous? Are the side effects of over clocking of RAM and CPU are manageable? Is there any permanent damage for the hardware by over clocking RAM and CPU? Can I see the improvement really or it is superficial?
