DaveO: To put hard drive files onto a CD, you first have to convert the files and folders into a mass of 1's and 0's that will look like files and folders on a CD. That's an "image" of the CD.

Then you can burn that image to the CD, or you can save it on the hard drive as a "disk image file." That's the 'one big lump' you mentioned. If you burn an image file to a CD, Windows Explorer won't show you the image file on the CD as a single file; it'll show whatever files and folders were used to create the image file.

Some burning programs do it in two steps:
1. pick all the files you want to put on the CD and make a disk image file out of them; and
2. burn that image to the CD.
You can think of the disk image file as an intermediate stage.

Even programs that don't require the two-step process usually have it as an option. It may reduce the risk of errors to do it that way. If you do it all in a single step, that's called burning "on the fly."

Full Nero can do everything on the fly. But there are all sorts of partial Nero packages that are given out for free with burners. They try to make a nuisance of themselves so you'll want to buy the full package.

The free program I use, InfraRecorder, can copy files to a CD on the fly, but not to a DVD. I have to make a disk image file first, and then burn that to the DVD.

I've never been able to figure out how to get ImgBurn to do anything except burn an image file to a CD or DVD. I can't figure out how to get it to convert a set of hard drive files into a disk image file, or to do anything on the fly. After reading what everyone wrote here, I tried again, but it's over my head.