Wikipedia helpfully explains:
The yobibit is a multiple of the bit, a unit of digital information storage, prefixed by the standards-based multiplier yobi (symbol Yi), a binary prefix meaning 2^80. The unit symbol of the yobibit is Yibit or Yib.1 1 yobibit = 2^80 bits = 1208925819614629174706176 bits = 1024 zebibits The zebi and yobi prefixes were originally not part of the system of binary prefixes, but were added by the International Electrotechnical Commission in August 2005.
Now, what in the world actually takes up 1,208,925,819,614,629,174,706,176 bits? The information content of the known universe? I guess this is forward thinking -- maybe astrophyics or nanotech, or even DNA analysis really will require these orders of magnitude.
How far off do you think all this is? Are these really meaningful units?