(mathematics) In a number system, the base determines the greatest number that can be represented by a single digit, which is one less than the base. The decimal system operates on the base 10 (decimal is Latin for one tenth; deci means 'having ten'), binary on base 2, and hexadecimal on base 16.
Using the examples above, the digits used in binary, decimal, and hexadecimal are 0 and 1, 0 through 9, and 0 through 9 and then A through F, respectively.
Normally we like to write numbers with more than one digit, so digits are multiplied by the base of the system depending on their position from the right end of the number. 0 is used as a placeholder. Thus, 10 in base 2 is the same as 2 in base 10, since the digit 1 has two times (from the base) the value of what it had been if it had been in the rightmost position, where the 0 is.
And no, it is not belong to The Laziest Men On Mars.
Thanks to ariels for certain amendments.