different between pingback vs ringback

English

ping +? back

pingback (plural pingbacks)

(Internet) A message automatically sent to a blog when one of the blogger's entries is referenced by another blogger.

ring +? back

ringback (uncountable)

(telecommunications) The sound transmitted back to a caller to indicate that the telephone they are calling is ringing.
(telecommunications) A telephone feature allowing a person to receive an automatic call back when a busy line becomes free.

Send