Extensions folder: Contains individual extensions that modify the operation of your computer. Unlike a control panel, an extension works automatically, without your intervention. See the "About the Extensions Folder" document in the Apple Extras folder for more information.
Fonts folder: Contains font suitcases or individual font files. You can place up to 128 suitcase or font files in this folder. PostScript fonts are not included in the 128 file limit. Font suitcases can hold any number of font files, up to a limit of 16 MB.
Launcher Items folder: Contains files, folders, and applications that appear in the Launcher window.
Macsbug: A debugger used by programmers to help diagnose problems with programs, extensions, and so on. Unless you're programming, you don't need Macsbug.
Note Pad: Stores text placed on the Note Pad. (The Note Pad is available in the Apple menu.)
Preferences folder: Contains preferences files created by individual applications. A preference file determines application settings.
PrintMonitor Documents folder: Contains printer files of documents waiting to be printed (if background printing is on in the Chooser).
Scrapbook: Stores items placed in the Scrapbook. (The Scrapbook is available in the Apple menu.)
Shutdown Items folder: Contains applications or scripts that run automatically when you shut down your computer. You can add or remove items from this folder.
Startup Items folder: Contains applications or scripts that run automatically when you start your computer. You can add or remove items from this folder.
System file: Contains some system-wide resources, such as sounds and keyboard layouts.
Universal Enabler: Provides additional system software for your computer.