Information stored on nonvolatile media is typically organized in files. In a modern OS such as Linux a file contains an ordered sequence of bytes. For instance a text file will contain many bytes, each of which represents a character or portion of a character.

Files are stored inside special files known as directories (or folders). Directories can further be stored inside other directories.

On the Linux system there is one directory which all other directories live under. That is the root directory and is referenced as "/". One of the directories under "/" is "bin". We can refer to it as "/bin". User's home directories are located under "/home". Since my login is "abrown", my home directory is "/home/abrown".

In the example above, the class.jpg file in my home directory would have the full path name /home/abrown/class.jpg.

If you want more information along this line I suggest you read http://www.freeos.com/articles/3102/ .

The OS does the work of decoding files into directories and regular files, and also of extracting the bytes for those files. While the details of that are very interesting, they are too far advanced for this introductory class. To explore this please read http://e2fsprogs.sourceforge.net/ext2intro.html