Files and Hardware

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.)

• When a file is read the hardware delivers some of those bytes to the program.
• When a file is written the hardware accepts some bytes from the program and saves them in part of the file.

The hardware makes no distinction between (say) image files and text files. Its all bytes to the hardware. What those bytes are being used for is up to the software.

You can think of a hard disk as being 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.