A trit is the tri­nary ana­log of the Bit: Where a bit says 2, a trit says 3. “Trit,” like “bit,” is over­loaded:

  • An ab­stract trit (ana­log of the ab­stract bit) is an el­e­ment of a set with three el­e­ments. Thus, there are three ab­stract trits. They are of­ten de­noted 0, 1, and 2.

  • A trit of data (ana­log of a bit of data) is the amount of data that can be car­ried by a phys­i­cal ob­ject that can be placed in any one of three states.

  • A trit of in­for­ma­tion (ana­log of a shan­non) is the amount of in­for­ma­tion some­one re­ceives when they start out max­i­mally un­cer­tain about which one of three out­comes hap­pened, and then they learn which one hap­pened. A trit of in­for­ma­tion is \(\log_2(3)\approx 1.58\) bits of in­for­ma­tion.

  • A trit of ev­i­dence (ana­log of a bit of ev­i­dence) in fa­vor of a hy­poth­e­sis is an ob­ser­va­tion that is three times as likely if the hy­poth­e­sis is true (ver­sus if the hy­poth­e­sis is false).

“Trit” is a port­man­teau of “tri­nary digit.”