

You can transfer your files and data to iCloud to save up some space on your Mac. Apple developers have already anticipated the problem with slow running Macs. It knows what to clean and where to clean, and is incredibly safe to use.

It cleans up your entire Mac, the easy stuff and the hard stuff. However, the hard part is cleaning up your system, and figuring out all the stuff that can be safely removed for more space. Nothing slows down a Mac more than having too much on your hard drive.
