Take a look at this comprehensive article for some of the most common types of hidden files and folders you’ll see. Now that you’ve revealed a ton of files on your Mac, you might be wondering what they are and what they do. What Type of Files are Hidden in Mac OS X? In a worse case scenario, you could accidentally edit and damage a critical file needed by an application or the operating system itself, which would necessitate a reinstall. There’s a reason why Apple decided to hide these items in Mac OS X. Use caution when accessing hidden files and folders. The hidden files and directories are displayed with dimmed icons, as shown below.
