It's important to understand that there are two ways to write to a CD:
-ISO Standard
-UDF (also known as "packet writing")
They are totally different.
ISO Standard writing is done with a CD burning application (Nero or Easy
CD-Creator) that you open and explicitly create a layout and burn the CD.
UDF is a "drag and drop" application, the CD is made to appear to the
user like a floppy disk.
ONLY UDF writing involves "formatting" the CD AT ALL. The whole concept
does not apply to ISO Standard writing.
Windows does ISO standard writing, but makes it look kind of like UDF.
It saves copies of the files to be written to the CD in a special system
folder, then burns them all at once.
It's important to understand that UDF format CDs are not "ISO Standard".
In general, this means that may well not be recognized on any computer
other than the one that they are written on, or that has the same or a
compatible UDF software package installed.
Both Nero and Roxio come with both ISO and UDF software. The UDF
components are called "Direct CD" (Roxio) and "In CD" (Nero), or
sometimes "Drag to Disc" (a widely used term).
Now I'm going to get controversial: It's my opinion (and only that)
that UDF should simply never be used, at all, ever, period. And
normally, when I install Nero or Roxio software, I don't even install it
(which requires a "custom" installation, because both packages, by
default, do install this software). UDF is one of those standards that
was developed for the purpose of "dumbing down" CD writing so that
non-techies could do it without knowing how to use a CD burning
application or knowing anything at all about a CD layout. However, in
my experience, it's caused more problems than it solved, and has
muddied, rather than clarified the use of burnable CDs. The dummies for
whom UDF was created simply have no idea what they are doing, they try
to do things that are illogical, that don't make sense and they have no
concept that they are being exposed to different elements of two
entirely different worlds without understanding either one of them.