Why should a distinction between RAW and non-RAW really be necessary? That's what is nice about applications like Lightroom and Aperture -- they let you work with RAW files as though they were "RGB" files. Edit your files, without worrying about what the underlying representation is.
Because it doesn't matter. Both Lightroom and Aperture apply NO changes to the original files, whether they are RAW or TIFF files. They store changes as "adjustments" in the database, and apply the corrections ONLY in the case that you export to a format such as TIFF or JPEG (often for a final output step).
Your question from a "novice" user indicates they still don't understand what's going on. With tools like ACR you have a definitive input and output step -- output of ACR is a PSD file that is opened by Photoshop, and at that time the file has had permanent changes applied. In Lightroom and Aperture, this need not happen. Apple's marketing focuses on clarifying this distinction a bit, perhaps it's a good reference for this.