binary

Meaning two. The principle behind digital computers. All input to the computer is converted into binary numbers made up of the two digits 0 and 1 (bits). For example, when you press the "A" key on your keyboard, the keyboard circuit generates and transfers the number 01000001 to the computer's memory as a series of pulses with different voltages. The bits are stored as charged and uncharged memory cells or as microscopic magnets on disk and tape. Display screens and printers convert the binary numbers into visual characters.

Circuits Are Binary
The electronic circuits that process these binary numbers are also binary in concept. They are made up of on/off switches (transistors) that are electrically opened and closed. The current flowing through one switch turns on (or off) another switch, and so on. These switches open and close in nanoseconds and picoseconds (billionths and trillionths of a second). See Boolean logic.

Make the Spot Smaller
Flip the Switch Faster
A computer's capability to do work is based on its storage capacity (memory and disk) and internal transmission speed. Greater storage capacities are achieved by making the memory cell or magnetic spot smaller. Faster transmission rates are achieved by shortening the time it takes to open and close the switch. In order to increase computer performance, we keep improving binary devices.

How Binary Numbers Work
Binary numbers are actually simpler than decimal numbers as they use only the digits 0 and 1 instead of 0 through 9.

In decimal, when you add 9 and 1, you get 10. But, if you break down the steps, you find that by adding 9 and 1, what you get first is a result of 0 and a carry of 1. The carry of 1 is added to the digits in the next position on the left. In the following example, the carry becomes part of the answer since there are no other digits in that position.

             carry--1
                     9
                  +  1
                  ____
                    10

The following example adds 1 ten times in succession. Note that the binary method has more carries than the decimal method. In binary, 1 and 1 are 0 with a carry of 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

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1.	(mathematics)	binary - Base two. A number representation consisting of zeros and ones used by practically all computers because of its ease of implementation using digital electronics and Boolean algebra.
2.	(file format)	binary - binary file.
3.	(programming)	binary - A description of an operator which takes two arguments. See also unary, ternary.