CLI, accessing another drive

[Glenn]

Hi,
I know that other drives are devices such as /dev/sdb, or /dev/hdc, and the 
like.
But I am messing with Arch Linux, with Speakup, and I want to install Voxin, 
and I will plug in a thumb drive, it will probably be /dev/sdd.
can I just work my way to the folder in Arch that I want to put the install 
file, and do something like:
cp /dev/sdd/voxin-enu-4.3.tgz
and bring it in?
I am used to copying files with Ubuntu, and only using the CLI for 
installation of the files.
Glenn