What is File?
In Linux and other UNIX-like operating systems is that “everything is a file”. It means you can see most of the things under file systems. You can see some files represents network device, disk, hardware devices etc. These are known as special files.
File Types in Linux:
Basically, there are three types of files. The first character in file permissions under ls -l commands shows the type of file. See the below screenshot and find the type of file matching with table given below the image.