techie help please

so help please
a. i have a mac
b. the mac is running OS X and had a dvd drive
c. i have a data dvd of photos i want to look at
d. dvd drive is not reading the data dvd

why? is it a bad dvd? should a standard dvd drive read a data dvd or do you have to have a specific and fancy data dvd drive to read more than just formatted film dvds?

frustrated.

have restarted twice and reloaded dvd in and out of machine a zillion times and the computer still isn't seeing it.