The whole story is this: on each directory (call them "folders" if you prefer) there are always, at least, two subdirectories within it. Those to entries are created at the very same time you create that folder.
You can see them if you cd into any dir and use this command:
One is '.', which points to the same directory. As silly as it seems, it has it's uses, as you have already discorered. For example, if you are into /home/foo/docs/autralopitecus/ and you can to copy a file from /mnt/cdrom/myphotos/, you don't have to write the two paths. You just do:
Code:
cp /mnt/cdrom/myphotos/whateverfile.jpg .
Instead of this one, which is equivalent:
Code:
cp /mnt/cdrom/myphotos/whateverfile.jpg /home/foo/docs/autralopitecus/
The second misterious entry is '..' (two dots), which means "the parent dir". So, if you are into a given dir, and you want to move a file from that dir to the previous (as in parent) one, then you just do
Or whatever. Always use with caution and double check before moving stuff around.
This is not exclusive to linux. Unix, bsd, msdos and even windows use this same dot and dot-dot stuff, only that you don't see that when you are clicking into a window.