Binary is a number system primarily used as binary code, which is given to the computer as instructions to tell it what to do. As seen above, binary can be used to display decimal numbers. Binary is base 2, which means it has two digits, 1 and 0. Binary numbers can be converted into decimal by adding powers of two as seen in the chart below.
Binary is made up of two digits so that the computer can understand it, but it can be thought of as 1 means “on”, and 0 means “off”. So if that number place is “on” then you multiply it by 1, and it is added to the result. If it is “off”, then you do not use that number place.