Hello Jax and Mark
High res. photos are the equivalent to a negative. These days most (if not all) print labs accept CDs and DVDs as well as a number of other digital storage devices. The biggest difference between CDs and DVDs is the storage capacity - DVDs store more info. Yes, you can transfer photos from a DVD to your computer with ease. In terms of using your photos on Facebook, I would recommend 72dpi (standard for web) and 1024x768 pixels. Your photographer should be able to use their software program to resize your photos for web usage. Happy to help. (PS Love St. Catherines - have family just down the road. :-))