Most of them are system files, preference files, bits of applications (an OS X application is actually a bundle, or a sort of folder containing thousands of files), and more. Naturally, you haven’t created all those files. You can see this number on your Mac by opening Disk Utility (which is in your /Applications/Utilities folder), selecting your drive, and then clicking the Info button in the Disk Utility toolbar-then scroll down to the File Count entry.
Your Mac is full of files: big ones, small ones documents, music files, photos, videos, and system files. A quick check of my iMac’s 256 GB SSD shows that it contains more than 60 million files. How To + Recommended Removing Duplicate Files on Mac OS X: The Complete Guide
