A filename is a string used to uniquely identify a file stored on the file system of a computer. Before the advent of 32-bitoperating systems, file names were typically limited to short names. Modern operating systems now typically allow much longer filenames.
In DOS, Windows, and OS/2, the root directory is "drive:\", for example, the root directory is usually "C:\". The directory separator is usually a "\", but the operating system also internally recognizes a "/". Physical and virtual drives are named by a drive letter, as opposed to being combined as one. This means that there is no "formal" root directory, but rather that there are independent root directories on each drive. However, it is possible to combine two drives into one virtual drive letter, by setting a hard drive into a RAID setting of 0.
Windows 10
The following folders may appear in the root of a boot partition.
32-bit architecture: All programs are installed in this folder. 64-bit architecture: 64-bit programs are installed in this folder.
\Program Files
Appears on 64-bit editions of Windows. 32-bit and 16-bit programs are by default installed in this folder, even though 16-bit programs do not run on64-bit Windows.
\ProgramData
Contains program data that is expected to be accessed by computer programs regardless of the user account in the context of which they run. For example, a program may store specific information needed to operateDVD recorders or image scanners connected to a computer, because all users use them. Windows itself uses this folder. For example, Windows Defender stores its virus definitions in \ProgramData\Microsoft\Windows Defender. Programs do not have permission to store files in this folder, but have permission to create subfolders and store files in them. The organization of the files is at the discretion of the developer.
\Users
User profile folders. This folder contains one subfolder for each user that has logged onto the system at least once. In addition, it has two other folders: "Public" and "Default". It also has two folder like-items called "Default User" and "All Users".
\Windows
Windows itself is installed into this folder.
Unix
and Unix-like operating systems use the Filesystem Hierarchy Standard as the common form for their directory structures. All files and directories appear under the root directory "/", even if they are stored on different physical devices.
