A typical computer operating system is made up of folders, which contain data relevant to the software applications maintained on the computer. These folders, which are called directories, are the indexes for the software applications and operating system to manage specific files for the computer. It is normal to find that a directory contains a subdirectory within it, which is simply another directory within the directory tree of an operating system.
A subdirectory is nothing more than a directory within another directory or a folder within a folder. All directories can become a subdirectory except for the master directory, which is typically referred to as the root directory or the parent directory. The root directory is the primary directory located at the top of the directory tree.
A directory is a folder that contains files of information relevant to specific tasks. Many of these folders are modifiable both in name and contents. As with any directory, they can also be moved or copied into another directory within the operating system.
Within most operating systems, thousands of files are created for managing the normal operations of the computer. These file systems are fairly complex and require a significant directory tree structure for successful management. It is typical to find that a specific directory may contain subdirectories that are protected from modifications by the user. This protection is necessary to ensure operational stability within the computer operating system.
It is important to create a meaningful directory tree when using any operating system, as this ensures proper identification of critical information in the future. The directory tree can be compared to the index catalog that is typically found at most libraries. This directory is the primary method of finding information under a specific topic and the subdirectory is a further delineation of the information around a specific topic.
Many graphical user interfaces (GUI) and operating systems can only maintain a limited number of subdirectories within a directory. Though this differs by software application, it is best to keep a subdirectory limited to a manageable level of separation. Too many levels of subdirectories become difficult to maintain and should be avoided.
An interesting feature for directories within most operating systems is the ability to hide files. Hidden files or hidden subdirectories, are a method of protecting information from users or hackers of the computer. A hidden directory is a marker that is placed on a directory to identify the folder as hidden, which will cause a search to skip the protected folder or subdirectory.