Glossary

A

API. An interface by means of which one software component communicates with or controls another. Usually used to refer
to services provided by one software component to another, usually via software interrupts or function calls
Aperture. The opening in an optical system defined by a lens or baffle that establishes the field of view.
Application Programming Interface. See API.
ANSI Terminal. A display terminal that follows commands in the ANSI standard terminal language. For example, it uses
escape sequences to control the cursor, clear the screen and set colors. Communications programs support the ANSI
terminal mode and often default to this terminal emulation for dial-up connections to online services.
ASCII. American Standard Code for Information Interchange. A 7 bit-plus-parity code representing 128 letters, numerals,
punctuation marks and control characters. It is a standard data transmission code in the U.S.
Autodiscrimination. The ability of an interface controller to determine the code type of a scanned bar code. After this
determination is made, the information content is decoded.

B

Bar. The dark element in a printed bar code symbol.
Bar Code. A pattern of variable-width bars and spaces which represents numeric or alphanumeric data in machine-readable
form. The general format of a bar code symbol consists of a leading margin, start character, data or message character,
check character (if any), stop character, and trailing margin. Within this framework, each recognizable symbology uses
its own unique format. See Symbology.
Bar Code Density. The number of characters represented per unit of measurement (e.g., characters per inch).
Bar Height. The dimension of a bar measured perpendicular to the bar width.