As far as the hardware of a computer system is concerned, all files look alike. Each file is regarded by hardware as a collection of bytes. (Remember that a byte is 8 bits.)
The hardware makes no distinction between (say) image files and text files. Its all bytes to the hardware. What those bytes are used for is up to the software.
A hard disk is like a bookshelf with many books on it—novels, picture books, text books, note books... The bookshelf works the same for all books, since all books are fundamentally alike. Of course, some readers specialize in some kinds of books, but that is a "software" distinction, not a property of the storage hardware.
The program Notepad processes text files but can make no sense of a MS Word file. Does this mean that those are fundamentally different file types?