Outlook folders are a lot like the folders in the Windows file system. A folder in Outlook can have subfolders under it, and subfolders can also have their own subfolders. The main differences between Outlook folders and Windows folders are that Outlook folders can contain only certain types of items, based on the folder type, and all Outlook folders are within the Outlook data store and are not available outside the Outlook data file.
You can create very complex arrangements of folders that suit your needs and the way you want to store things in Outlook. Figure 10.1 shows an arrangement of folders and subfolders in the Folder List.