#### Binary digit

Data the computer deal is all digital data. Even though the digital data, there is only "off" and electrical "on" in there. And if ON "1", and the "off" if "0", I only exist only two digits.
In one bit I can represent two ways of "0" and "1".

Then, in the 2-bit I can represent one of four "00" "01" "10" "11".

In 256 2 ^ 8 in 8-bit, you will be able to represent the number of 0-255.

So why, can computers only handle two numbers ,”0” and “1”? The principle is that it is similar to Morse code, combining “1” or “0”, can be express more numbers.

Thus, even if there are only two digits, it can handle a variety of data by combining “1”number of “0”. This is the concept of “Binary digit”.