A numeral format consisting only of the numbers 1 and 0; other interpretations include "yes or no", "
true or false", "on or off", et cetera. This format is largely used in devices where
calculation is a key component; from a simple calculator to the most powerful supercomputers.
A number in this format is composed of bits, with each successive bit (from right to left) being twice the value of
the bit "before" it, hence the alternate title of "base-2 number system". If there are "n" total bits, the value of the first bit will be 2 ^ (n - 1). This bit is the largest fraction, always greater than, but not equal to, half of the whole number.
The last bit in a
binary number always represents "one", and this makes it quite important as well. If this bit is off, the number will be either even, or, if only one bit is present, just "zero". Turn this
bit on, and the number will become odd.
Binary can be easily converted to a different format by partitioning the bits symmetrically, again from right to left. If the bits are split into
threes, the number can become base-8 or
octal, while being split into sets of four can make the number base-16 or
hexadecimal. It is also possible to convert to base-10 simply by starting from the right and adding 2 ^ (i - 1) each time bit "i" is equal to 1, until you reach "n".
Example:
My current age is
10100. No, I'm not ancient, that's just another way of saying I'm
20 years old. The current year, which is 2020 at the time of
this post, is also 11111100100 in binary.