Add up there to keep the desktop clear, of course they could go down onto the desktop area if you wanted too.
Left to right...
Upper left is Applications, similar to the Start button.
Firefox - you know, browser.
Evolution Mail - similar to outlook express.
File Browser - similar to windows explorer.
Terminal - command line.
Bluefish - for editing HTML, PHP files.
gFTP - upload/download files via file transfer protocol(FTP), something like FileZilla, etc.
Trash - similar to recycle bin.
Network - lets you know you are online or not.
Sound - pretty much the same as windows.
Correction edit, again.