Oh, I get ya now. You want software which makes ISO's or some image of the CD or DVD. 1:1 copies.
I would suggest DVD Decrypter for DVD's. While this software is free it is infact as good as software you usually need to pay for. Other companies have actually based their software on it, and sold the resultant program, which is sad.
Making a 1:1 copy of an Audio CD is however more difficult (especially if the Audio CD has other data on it). This is because Audio CD's don't have error correction, which, to cut a long story short, means your software needs to be able to re-verify/confirm that the audio has been copied to hard disk fully and completely. Exact Audio Copy is the only software that can do the main Audio part correctly -- no errors. It may not completely keep the CD structure however.
If you've got an Audio CD with other data on it, EAC won't copy this.
I suppose you could use software like ISOBuster of CDRWIN, but these have no easy way of re-verifying/confirming that your Audio is without errors, you'll just have to listen to the CD after.
Here is another forum discussion (at Hydrogen Audio -- top quality audiophile site) on copying Audio CD's in their entirety, and even there, there isn't a solid 100% accurate solution. It's a recently dated discussion too:
EAC and CD-Extras/Mixed mode
ps - On-the-fly is when you copy a CD/DVD from one CD/DVD drive source and have that data etc incrementally burnt onto another CDR/DVDR etc, using another CD/DVD burner. No data, or hardly any data, is stored on the hard disk first, so this puts more strain on the CD/DVD equipment as they're both being accessed for long periods.