A virtual file system (VFS) is a software layer that abstracts the underlying file storage and access mechanisms of a computer system. It provides a common interface for accessing files, regardless of where the files are physically stored or how they are accessed.
The VFS allows applications to access files stored on various devices and file systems, such as hard drives, USB drives, and network file servers, using a uniform set of commands. This makes it easier for developers to create applications that can access and manipulate files on different types of systems.
For example, consider an application that needs to access a file stored on a network file server. Without a VFS, the application would need to be specifically designed to access files on that particular type of server using the server's native protocols and file access methods. With a VFS, the application can access the file using the same set of commands that it would use to access a file stored on a local hard drive, regardless of the type of file server.
The VFS also provides a layer of abstraction between the application and the physical file storage, which makes it easier to manage the file system and make changes to the underlying storage without affecting the application.
Some examples of VFS implementations in popular operating systems include the Virtual File System (VFS) in Linux and the Virtual File System (VFS) in macOS.