basic optical drive question....

at least i think. is it possible for a DVD and/or a CD burner can read disks?

ex. i wanna watch a movie one day and i can just pop a dvd in the drive to watch it. (is that possible?)

Yes it is possible. If it can burn to it, it can read from it. I stick with a CD-RW and a DVD-RW in my rig, although I am thinking about getting rid of the CD-RW and just going with a single SATA DVD-RW to try to keep cable management better, and because I really don't need both, since the one drive will burn and read both kind of discs.

If you have a newish DVD burner you'll be able to watch most DVD movies. It helps if you have the right software. I use this.
http://majorgeeks.com/K-Lite_Mega_Codec_Pack_d5230.html
Now you can watch all DVD movies.