again about cdw sdw

sarir_sss

what is difference among conception of ; (in)commensurate(cdw sdw) ;and ;(an)isotropy(lattice); and ;symmetry in lattice؟ how these concepts related in cdw or sdw?
what is strain wave?
what is flappy force?(in cdw sdw)
plz tell me about specific resistance behavior in cdw, sdw?what is meaning it?(resistance cdw,sdw)?

thanks alotttttttt plz help me