In terms of computer operating system,all the data are organized into file.all the file are organized into directories are organized into tree structure called the 'File System'.
In linux,everything is configured as a file.this includes not only text files,images and compiled programs,but also directories,partitions and hardware device drivers.
Linux supports numerous file system,Microsoft NTFS,VFAT,and many other file system.every item stored in a linux file-system belongs to one of four types.
An ordinary file is a file on the system that contains data,text or program instructions.(Unlike other operating systems,linux filenames are not broken into a name part and an extension part(although extension are still frequently used as a means to classify file).instead they can contain any keyboard character except for '/' and be up to 256 characters long.
Some special file provide access to hardware such as hard drives,CD-drives,modems.
Directories are containers or folders that hold file,and other directories.for users,it is similar with windows OS,Mac OS(Unix directories are equivalent to folders.)
Top provide applications with easy access to hardware device,linux allows them to be used in much the same way as ordinary file.there are two types of devices in linux block oriented device which transfer data in blocks and character oriented devices that transfer data on a byte by byte basis.
A link is a pointer to another file.there are two type of link - a hard link to a file is indistinguishable from the file itself.a soft link provides an indirect pointer or shortcut to a file. a soft link is implemented as a directory file entry containing a pathname.