If you have a CDR/DVD+RW (Read Write), then you can burn CDs and DVDs. Most, if not all, DVDs are encrypted so you can't burn them though.
There are programs you can download that overwrite the encryption....I haven't tried it. The most I've done with burning DVDs is making multiple copies of photos and videos on a DVD for family and friends.
Depends on the type of combo. It seems many computers come with DVD-ROM/CD-RW combos which can play DVDs and CDs but can only burn CDs (I know the DVD-ROM I bought for my computer is also a CD-RW). If it says DVD-RW anywhere on it, then it can burn DVDs, and usually CDs (I think all burn CDs, but there could be some out there that don't)
When I bought our computer last year, every computer store employee told me if I wanted to burn DVDs, I needed a DVD+RW. A DVD R will just read them, not burn. Just read everything carefully, John. The more details you get, the better.
A CD-RW/DVD drive , also called a CD/DVD Combo Drive, can read data from CDs and DVDs, and can burn recordable CDs.
Generally, since everything is backward compatable, they call DVD Burners, well, DVD Burners. As it stands now, ALL DVD Burners can burn CDs as well. Plus, I haven't seen a burner on the market that doesn't do + or - in a long time.