The Bit is the simplest form; it's a signal that can be true or false, with its official English equivalents being “TRUE” or “FALSE,” or even simply 0 or 1. There is no 2 anymore because two is represented by 10 according to the rules of the binary number system, which in this case is not ten but one zero. To clearly distinguish this, we write numbers in the decimal number system “just like that,” for example, 10. If this is a number in the binary number system, then we denote it as 2#10.