We can represent the binary states of “on” and “off” as numbers. The binary number system is based on only two digits: one and zero. For a binary state of on, that’s represented by a one. For a binary state of off, that’s represented by a zero.
But storing a single value doesn’t make much sense on its own. You would want to store multiple values in a row. To do that, you would create a string of them, and since they are all numbers, you are just creating a larger number with multiple digits or bits.