Punched card

A punched card (also punch card) is a stiff paper-based medium used to store digital information via the presence or absence of holes in predefined positions. Developed over the 19th to 20th centuries, punched cards were widely used for data processing, the control of automated machines, and computing. Early applications included controlling weaving looms and recording census data. Punched cards were widely used in the 20th century, where unit record machines, organized into data processing systems, used punched cards for data input, data output, and data storage. The IBM 12-row/80-column punched card format came to dominate the industry. Many early digital computers used punched cards as the primary medium for input of both computer programs and data. Punched cards were used for decades before being replaced by magnetic-tape data storage. While punched cards are now obsolete as a storage medium, as of 2012, some voting machines still used punched cards to record votes. Punched cards had a significant cultural impact in the 20th century. Their legacy persists in modern computing, influencing the 80-character line standard still present in some command-line interfaces and programming environments.