Maybe your Mac isn’t running as well as it used to. Maybe one or more of your apps are behaving strangely. Perhaps you are concerned about your privacy online or what companies and app developers know above you. All these are good reasons to clear the cache on your Mac. But before we run through how to do that we’ll explain what cache is, why you might benefit from deleting it, how you can delete your cache, and why you should be careful about what you do delete.
What is cache?
A cache is where data is stored to help your Mac speed up various processes.
You have probably heard of the cache associated with web browsers. This cache contains the data that gets downloaded to your Mac and is saved so that the next time you visit the same website some of the data is already downloaded and it won’t take so long to load up the page.
Read more at Macworld.com