# What Is a Binary System and Why Do Computers Use It?

Computers and other electronic systems work faster and more efficiently using the binary system, because the system’s use of only two numbers is easy to duplicate with an on/off system. Electricity is either on or off, so devices can use an on/off switch within electric circuits to process binary information easily. For example, off can equal 0 and on can equal 1.

Every letter, number, and symbol on a keyboard is represented by an eight-bit binary number. For example, the letter A is actually 01000001 as far as your computer is concerned! When you study basic computer programming, you learn early on that basically everything that goes into (input) or comes out of (output) a computer is comprised of a series of 0s and 1s. That’s the essence of digital data, and it’s based upon the binary system.

The modern binary number system was devised by Gottfried Leibniz in 1679 and appears in his article *Explication de l’Arithmétique Binaire* (published in 1703). Systems related to binary numbers have appeared earlier in multiple cultures including ancient Egypt, China, and India. Leibniz was specifically inspired by the Chinese I Ching.

When you learn math at school, you use a base-10 number system. That means your number system consists of 10 digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9, when you add one to nine, you move the 1 one spot to the left into the tens place and put a 0 in the ones place: 10.

The binary system, on the other hand, is a base-2 number system. That means it only uses two numbers: 0 and 1. When you add one to one, you move the 1 one spot to the left into the twos place and put a 0 in the ones place: 10. So, in a base-10 system, 10 equals ten. In a base-2 system, 10 equals two.

In the base-10 system you’re familiar with, the place values start with ones and move to tens, hundreds, and thousands as you move to the left. That’s because the system is based upon powers of 10. Likewise, in a base-2 system, the place values start with ones and move to twos, fours, and eights as you move to the left. That’s because the base-2 system is based upon powers of two. Each binary digit is known as a bit.

Don’t worry if the binary system seems confusing right now. It’s fairly easy to pick up once you work with it a while. It just seems confusing at first because all numbers are made up of only 0s and 1s. The familiar base-10 system is as easy as 1-2-3, while the base-2 binary system is as easy as 1-10-11.