I noticed some games for sale or trade are DVD.
So do you need a separate DVD player for these or can you put them into the Cd slot?
thanks!

That depends on whether your "CD slot" has a drive that is capable of reading CD's behind it. Almost any recent computer comes with a drive that is capable of reading DVD's as well as CD's. Do you know the model number of your drive? Or of your computer?

It has a slot that says DVD on it and I've been putting regular cd games in there so maybe all is well.
It says Writemaster on the front but I can't get to the back of it for the model number.
Thanks!

Write master is manufactured by Samsung, yours sounds like a super-multi type (it will read both CD and DVD's).