Hello corn29,
As shad0w_walker says, any file prefixed with . is hidden.
In a terminal, you can use the -a option of the "ls" command.
Your cdrom is automounted in /media, so:
Code:
ls -a /media/cdrom/
will list ALL the documents in your directorie.
You'll always see a . and a .., respectively "the directorie itself" and "the parent directorie".
Code:
cd /media/cdrom
ls -al
cd ..
will move you to the parent dir, /media in your case.
The . is useful when you want, for example, copy (cp) something from "there" to "where I am":
Code:
cp /home/Desktop/something.txt .