Subject: 'zero mode' and 'kaluza-klein mode' of graviton, difference? how possible?

What is the difference between a "zero mode" and a "kaluza-klein mode" graviton?
Is a zero mode graviton massless because it has "no vibration (excitation)" in
an extra dimension(s)? and a kaluza-klein mode graviton appears massive because
it has some (standing wave?) vibration (excitation) in an extra dimension(s)? Is
this the case or not? But if so why "quantum jitter (=some kind of vibration?)"
in an extra dimension of a zero mode graviton does not make the graviton appear
massive? I mean, "quantum jitter" must exist in any dimension, and extra
dimensions cannot be empty of waves (=they all must contain some waves (with
non-zero energy? or possibly? with zero-energy on average???)). And, what about
other (massless) particles like photons and gluons? Could they be in
kaluza-klein (KK) mode (=in excitation?) and appear massive under specific
conditions? (=? Could they have (massive?) KK partners?)

Re: 'zero mode' and 'kaluza-klein mode' of graviton, difference? how possible?