A file is a container that holds information. Most of the files you use contain information (data) in some particular format--a document, a spreadsheet, a chart. The format is the particular way the data is arranged inside the file. The format of a file is known as its data type.
When File Manager is in one of its icon-view modes, you can identify the data type of a file by the icon used to represent the file. Each data type has a different icon.
Most application programs understand a limited number of data types. For example, a document editor probably cannot read a spreadsheet file. The desktop helps you recognize different types of files using a data-type database. In most cases, when you double-click a file, the desktop will automatically launch the application that understands that file's data type.
The maximum allowable length of a file name varies from system to system. Some operating systems do not allow file names longer than 14 characters. If necessary, consult with your system administrator.
A folder is a container for files, similar to a folder in a file cabinet. In fact, File Manager uses a folder icon to represent a folder. A folder can contain other folders--sometimes called subfolders. With folders and subfolders, you can create multiple layers of organization that form a hierarchy. In other contexts, folders are often referred to as directories.
Within any single folder, each file name must be unique. However, files in different folders may have the same name.
Since files and folders are both represented in File Manager as icons, the term object is used to describe them both. Objects are discrete things on the desktop that you can create and manipulate.
On the desktop, applications can also be represented as objects. For example, Application Manager contains objects representing the applications available on your system.
The location of a file is often specified by listing the folders and subfolders that lead to the file--this list is called a path. A file's path is visible in two places in File Manager. First it is shown in the iconic path as a string of folders. Second, it is shown in a text form in the text path line above the view area. These two areas can be turned off. (See "To Configure the Headers" for more information.)
The path to an object is a way to specify where the object is located in the file system. There are two ways to specify the path: absolute path and relative path.
A path is an absolute path if it begins at the root folder. The root folder is the single common folder on your system where the hierarchy begins. If a path begins with a slash (/), it is an absolute path specified from the root folder. For example, the following is an absolute path to the file letter:
A path is relative if it describes the location of a file or folder as it relates to the current folder. If you are in a folder and you want to move down the folder tree, you don't need to type the absolute path name. You can just type the path starting with the name of the next folder in the path. If a path does not begin with a slash, it is a relative path. For example, if the current folder is /usr/dt and you want to move to the folder /usr/dt/config/letters, you would use the following relative path:
Two special folder names are useful when specifying relative paths. The "." folder (sometimes called "dot") represents the current folder. The ".." folder (sometimes called "dot-dot") represents the parent folder--the folder one level up in the folder hierarchy. For example, if your current folder is /usr/dt/config, then the relative path to the Dtwm file becomes:
because the file is in the /usr/dt/app-defaults/language folder, one level above the current folder and in the app-defaults/language subfolder.
If you still want to learn more about your computer's file system, refer to the online help or documentation for your operating system. There are also many commercial books available that cover the basics of file systems and file management.