1.  terabyte(n = noun.quantity) tb - a unit of information equal to 1000 gigabytes or 10^12 (1,000,000,000,000) bytes;
is a kind of computer memory unit
is a part of pb, petabyte
has parts: g, gb, gigabyte

2.  terabyte(n = noun.quantity) tb, tebibyte, tib - a unit of information equal to 1024 gibibytes or 2^40 (1,099,511,627,776) bytes;
is a kind of computer memory unit
is a part of pb, pebibyte, petabyte, pib
has parts: g, gb, gib, gibibyte, gigabyte