New to the DC - Couple of simple questions

[Molko]

I am new the DreamCast copying scene, i wonder if someone could answer the following questions.

1)I understand the DC GDROM is capable of storing 1GB of information, so how is it that we are copying onto stardard CD's, which hold about 780Mb (approx) ?. Is some of the DC software not copyied or what - Can someone please explain.

2)I have been reading some of the previous posts, and it appears that the quality of the CD writer is important. Which is the best CD writer to use to copy DC Games.?