Definition: binary

(1) A binary is an executable program. See bin and bin file.

(2) Meaning two states (0 and 1). Binary is the basic operation in every digital device both for storage and execution. It is physically a charge in a storage cell or a voltage in a line. The utter simplicity of the binary concept created the architecture of modern technology. Except for quantum computers, everything is binary (see quantum computing).

Binary Goes Back to the 1600s
In 1623, English philosopher Francis Bacon created a secret alphabetic code consisting of the two letters "a" and "b." For example, his initials "FB" were coded as "aabab aaaab."

Internally Everything Is Binary
All input to a computer is converted to a 0 or 1. Pressing "A" on the keyboard generates the binary 01000001 and sends it to the computer's memory as on/off pulses defined by voltage levels. In memory, the bits are temporarily charged cells. In storage (SSD or hard drive), bits are permanent charges that are on or off, but can be erased.

Circuits Are Binary
The electronic circuits that process everything are also binary. They are on/off switches (transistors) that are electrically opened and closed. The current flowing through one switch turns on (or off) another, and so on. Switches open and close in billionths and trillionths of a second. See Boolean gates.

Smaller Spots - Faster Switches
A computer's capability to do work is based on the size of memory (the workplace), the size of storage (disk or SSD) and CPU speed. Memory has an upgrade limit but storage can be very large.

Design engineers achieve greater performance by making the cells and transistors smaller, which means less time to change their state from on to off or from open to close (see chip feature size). See bit, byte, binary numbers, binary values, binary file, binary standard and binaries.

How Binary Numbers Work
In the decimal numbering system, adding 9 and 1 produces a result of 0 in the 1s position plus a carry of 1. The carry jumps over to the 10s position on the left.

             carry--1
                     9
                  +  1
                  ____
                    10

Binary numbers use only the digits 0 and 1. The following example adds 1 ten times in succession in both base 2 (binary) and base 10 (decimal). The carry occurs many more times in binary because there are only two digits (0 or 1).

              Binary      Decimal

                 0           0

              +  1        +  1
              ____        ____
                 1           1

              +  1        +  1
              ____        ____
                10           2

              +  1        +  1
              ____        ____
                11           3

              +  1        +  1
              ____        ____
               100           4

              +  1        +  1
              ____        ____
               101           5

              +  1        +  1
              ____        ____
               110           6

              +  1        +  1
              ____        ____
               111           7

              +  1        +  1
              ____        ____
              1000           8

              +  1        +  1
              ____        ____
              1001           9

              +  1        +  1
              ____        ____
              1010          10

An Analog-Digital Watch

The hands are analog but the numbers are binary. It only takes four bits (8,4,2,1) to represent 12 hours. The hour hand is at binary 2 and 8. (Image courtesy of Cadence Watch Company.)