Actually if it says only Dvd-r it means it only READS dvd's but will also
read Cd's too. If it says dvd+/- Rw then you cna rewrite dvd's, also you
can rewrite cd's.

The dvd drive labeled with dvd+r/+rw/-r/-rw/cd-rw, well let me explain there
a few differing types of DVD media to write to out there, there are dvd-r,
dvd+r, dvd-Ram, dvd+rw, dvd-rw. Not all drives can read all types of media.
That drive described can read/write dvd+r/+rw/-r/-rw, also all dvd+/- Rw
drives can rewrite both types of cds.