Gain levels after ripping...

I would imagine that some software could process the data from the disc and set the gain to some specified level, but by default it should just be copying the data from the disc to the hard drive. My .WAV files all don't have the same level of gain when played back, just like the CDs.

A pure unprocessed rip of a CD will retain the volume data exactly as it was on the CD.

Some ripping programs may allow volume adjustment when ripping but that can be turned on or off, if even present.

And many of the programs for computer play of ripped music will allow for replay gain adjustment, but that is for playback only and doesn't permanently change the file itself.

Yes, some software will have an option to normalize, I think thats what it's called and it rips all cd's to same sound level.