How does Mac clean up the cache?

How does Mac clean up the cache? How does the Mac speed up the switch? Because I also have Apple computer, so I do not know much about it, but today in the forum to see a good post, it is said to improve the Apple Computer boot speed, shutdown speed, program cotton phenomenon Oh.

Instructions for use: This method is recommended for three months or so. Suitable for boot, shutdown, open the program, run the program cotton phenomenon.

Usage: Press the option command P R in an instant, restart the computer two or three times after the release, normal access to the system, and then shut down the restart two or three times, test speed, absolutely effective. The main is to clean up the system for a long time to run the accumulated cache.

In addition, you can also use the Reset system configuration, the method is: Power on instant hold down CONTROL option command for 10 seconds.

And it's said that even if you go to a direct store and ask them to help with the slow pace, it's the same. haha! We'll try it in person! Believe it will have effect!