DLT drive restoring from tar file with tar and cpio

I have found the following example in Essential System Administration Ore=
illy Press 3rd revision, page 736 although I have a question.

Example =

tar -xp /home/chavez/freeway/1.data
cpio -imd '*1.data' < /dev/rmt0
end of example

The books explanation of the example
The command restores the file /home/chavez/freeway/1.data from an archive=
made of /home located on the tape in the default tape drive. =


When you execute the first command "tar -xp /home/chavez/freeway/data" ho=
w does the shell know that it should execute the tar command on the data =
on the tape drive? =96 I suppose because it looks at the default tape dri=
ve.

for the 2nd command why is it necessary to have the "*" when only one fil=
e is being restored not all files that end with "data"? Also is the file =
restored to the current working directory or the location they were backe=
d up from?


Jim